The most important interaction of electrons with crystalline matter is the interaction with the electrostatic potential field. The scattering into sharp, Bragg reflections is considered in terms of the interaction of an incident plane wave with a time-independent, averaged, periodic potential field which may be written
where
is the unit-cell volume and the Fourier coefficients,
, may be referred to as the structure amplitudes corresponding to the reciprocal-lattice vectors h. In conformity with the crystallographic sign convention used throughout this volume [see also Volume B
(IT B, 2001
)], we choose a free-electron approximation for the incident electron beam of the form
and the interaction is represented by inserting the potential (4.3.1.1)
in the Schrödinger wave equation
where eE is the kinetic energy of the incident beam,
is the magnitude of the wavevector for the incident electrons, and σ is an `interaction constant' defined by
where h is Planck's constant. Relativistic values of m and λ are assumed (see Subsection 4.3.1.4
).
The solution of equation (4.3.1.2)
, subject to the boundary conditions imposed by the need to fit the waves in the crystal with the incoming and outgoing waves in vacuum at the crystal surfaces, then allows the directions and amplitudes of the diffracted beams to be obtained in terms of the crystal periodicities and the Fourier coefficients,
, of
by the eigenvalue or Bloch-wave method (Bethe, 1928
).
Alternatively, the scattered amplitudes may be obtained from the integral form of (4.3.1.2)
,
where
represents the incident beam, K = σ/λ, and the integral is taken over the space of the variable,
. An iterative solution of (4.3.1.4)
leads to the Born series,
where
and
for
. Terms of the series for
may be considered to represent the contributions from single, double and multiple scattering of the incident electron beam. This method has been applied to the diffraction from crystals by Fujiwara (1959
).
A further formulation of the scattering problem in integral form is that due to Cowley & Moodie (1957
) who considered the progressive modification of an incident plane wave as it passed through successive thin slices of a crystal. The effect of the nth slice on the incident electron wave is that of a phase-grating so that the wavefunction is modified by multiplication by a transmission function,
where
is the projection of the potential distribution within the slice in the direction of the incident beam, taken to be the z axis;
Propagation of the wave between the centres of slices is represented by convolution with a propagation function, p(xy), so that the wave entering the (n + 1)th slice may be written
In the small-angle approximation, the function
is given by the usual Fresnel diffraction theory as ![[p(xy)=(i/\lambda\Delta z)\exp\{-ik(x^2+y^2)/2\Delta z\}. \eqno (4.3.1.9)]](/teximages/cbch4o3/cbch4o3fd11.svg)
In the limit that the slice thickness,
, tends to zero, the iteration of (4.3.1.8)
gives an exact account of the diffraction by the crystal.
On the basis of the above-mentioned and other related formulations of the diffraction problem, several computing methods have been devised for calculation of the amplitudes and intensities of the many diffracted beams of appreciable intensity that may emerge simultaneously from a crystal (see Section 4.3.6
). In this way, a degree of accuracy may be achieved in the calculation of the intensities of spots in diffraction patterns or of the contrast in electron-microscope images of crystals (Section 4.3.8
).
All such calculations require a knowledge of the potential distribution,
, or its Fourier coefficients,
. It is usually convenient to express the potential distribution in terms of the sum of contributions of individual atoms centred at the positions
. Thus:
or, in terms of the Fourier transforms,
, of the
![[V({\bf h})=\textstyle\sum\limits_i V_i({\bf h})\exp\{+2\pi i{\bf h}\cdot{\bf r}_i\}. \eqno (4.3.1.11)]](/teximages/cbch4o3/cbch4o3fd13.svg)
As a first approximation, the functions
may be identified with the potential distributions for individual, isolated atoms or ions, with the usual spreading due to thermal motion. The interatomic binding and the interactions of ions that are thereby neglected may have important effects on diffraction intensities in some cases.
In this approximation, the Fourier transforms for individual atoms may be written
where
and the
are the Born electron scattering amplitudes, as conventionally defined, in units of Å. Here
is half the scattering angle and, again, K = σ/λ. Some values of
listed in the accompanying Tables 4.3.1.1
and 4.3.1.2
are obtained from the atomic potentials
for isolated, spherically symmetrical atoms or ions by the relation ![[f^{B}(s)=4\pi K \int\limits^\infty_0 r^2\varphi(r){\sin sr\over sr}{\rm d} r.\eqno (4.3.1.13)]](/teximages/cbch4o3/cbch4o3fd15.svg)
Element | H | He | Li | Be | B | C | N | O | F | Ne | Na |
---|
Z | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
---|
Method | HF | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 0.529 | 0.418 | 3.286 | 3.052 | 2.794 | 2.509 | 2.211 | 1.983 | 1.801 | 1.652 | 4.778 | 0.01 | | 0.418 | 3.265 | 3.042 | 2.788 | 2.505 | 2.209 | 1.982 | 1.800 | 1.651 | 4.749 | 0.02 | | 0.417 | 3.200 | 3.011 | 2.768 | 2.492 | 2.201 | 1.976 | 1.796 | 1.648 | 4.663 | 0.03 | | 0.415 | 3.097 | 2.961 | 2.736 | 2.471 | 2.187 | 1.966 | 1.789 | 1.642 | 4.527 | 0.04 | 0.51 | 0.413 | 2.961 | 2.892 | 2.693 | 2.442 | 2.168 | 1.953 | 1.779 | 1.635 | 4.348 | 0.05 | 0.51 | 0.410 | 2.800 | 2.807 | 2.638 | 2.406 | 2.144 | 1.937 | 1.767 | 1.626 | 4.138 | | | | | | | | | | | | | 0.06 | 0.50 | 0.407 | 2.622 | 2.710 | 2.574 | 2.363 | 2.116 | 1.917 | 1.752 | 1.615 | 3.908 | 0.07 | 0.49 | 0.404 | 2.435 | 2.601 | 2.502 | 2.313 | 2.083 | 1.893 | 1.735 | 1.602 | 3.667 | 0.08 | 0.48 | 0.399 | 2.245 | 2.484 | 2.423 | 2.259 | 2.047 | 1.867 | 1.716 | 1.587 | 3.425 | 0.09 | 0.47 | 0.395 | 2.058 | 2.362 | 2.339 | 2.200 | 2.007 | 1.839 | 1.694 | 1.570 | 3.190 | 0.10 | 0.45 | 0.390 | 1.879 | 2.237 | 2.250 | 2.138 | 1.963 | 1.808 | 1.671 | 1.552 | 2.967 | | | | | | | | | | | | | 0.11 | 0.44 | 0.384 | 1.710 | 2.111 | 2.159 | 2.072 | 1.918 | 1.774 | 1.646 | 1.533 | 2.759 | 0.12 | 0.425 | 0.378 | 1.554 | 1.987 | 2.067 | 2.005 | 1.870 | 1.739 | 1.619 | 1.512 | 2.569 | 0.13 | 0.411 | 0.372 | 1.411 | 1.865 | 1.974 | 1.936 | 1.821 | 1.702 | 1.591 | 1.490 | 2.395 | 0.14 | 0.396 | 0.366 | 1.282 | 1.748 | 1.882 | 1.866 | 1.770 | 1.664 | 1.562 | 1.467 | 2.239 | 0.15 | 0.382 | 0.359 | 1.166 | 1.635 | 1.791 | 1.796 | 1.718 | 1.625 | 1.532 | 1.443 | 2.099 | | | | | | | | | | | | | 0.16 | 0.366 | 0.352 | 1.063 | 1.528 | 1.702 | 1.727 | 1.666 | 1.585 | 1.501 | 1.418 | 1.974 | 0.17 | 0.353 | 0.345 | 0.971 | 1.427 | 1.616 | 1.658 | 1.614 | 1.545 | 1.469 | 1.393 | 1.863 | 0.18 | 0.338 | 0.338 | 0.889 | 1.332 | 1.533 | 1.591 | 1.561 | 1.504 | 1.436 | 1.367 | 1.763 | 0.19 | 0.324 | 0.330 | 0.817 | 1.243 | 1.453 | 1.524 | 1.510 | 1.463 | 1.404 | 1.340 | 1.674 | 0.20 | 0.311 | 0.323 | 0.753 | 1.161 | 1.377 | 1.460 | 1.458 | 1.422 | 1.371 | 1.313 | 1.594 | | | | | | | | | | | | | 0.22 | 0.285 | 0.308 | 0.646 | 1.013 | 1.235 | 1.337 | 1.358 | 1.341 | 1.304 | 1.259 | 1.458 | 0.24 | 0.261 | 0.293 | 0.562 | 0.887 | 1.107 | 1.222 | 1.262 | 1.261 | 1.238 | 1.204 | 1.344 | 0.25 | 0.249 | 0.286 | 0.526 | 0.832 | 1.048 | 1.168 | 1.216 | 1.222 | 1.206 | 1.176 | 1.295 | 0.26 | 0.238 | 0.278 | 0.494 | 0.781 | 0.993 | 1.117 | 1.171 | 1.184 | 1.173 | 1.149 | 1.249 | 0.28 | 0.218 | 0.264 | 0.440 | 0.690 | 0.892 | 1.020 | 1.085 | 1.110 | 1.110 | 1.095 | 1.167 | 0.30 | 0.199 | 0.250 | 0.396 | 0.614 | 0.803 | 0.932 | 1.006 | 1.040 | 1.049 | 1.043 | 1.095 | | | | | | | | | | | | | 0.32 | 0.182 | 0.236 | 0.359 | 0.549 | 0.725 | 0.853 | 0.932 | 0.974 | 0.991 | 0.991 | 1.031 | 0.34 | 0.167 | 0.224 | 0.328 | 0.494 | 0.657 | 0.781 | 0.863 | 0.911 | 0.935 | 0.942 | 0.973 | 0.35 | 0.160 | 0.217 | 0.314 | 0.469 | 0.625 | 0.748 | 0.831 | 0.881 | 0.908 | 0.918 | 0.946 | 0.36 | 0.153 | 0.211 | 0.301 | 0.446 | 0.596 | 0.717 | 0.800 | 0.853 | 0.882 | 0.894 | 0.921 | 0.38 | 0.141 | 0.200 | 0.279 | 0.406 | 0.543 | 0.658 | 0.742 | 0.798 | 0.831 | 0.849 | 0.872 | 0.40 | 0.130 | 0.189 | 0.259 | 0.371 | 0.497 | 0.606 | 0.689 | 0.747 | 0.784 | 0.805 | 0.827 | | | | | | | | | | | | | 0.42 | 0.120 | 0.178 | 0.241 | 0.341 | 0.455 | 0.559 | 0.641 | 0.700 | 0.739 | 0.764 | 0.785 | 0.44 | 0.111 | 0.169 | 0.226 | 0.314 | 0.419 | 0.517 | 0.596 | 0.656 | 0.697 | 0.725 | 0.746 | 0.45 | 0.107 | 0.164 | 0.219 | 0.302 | 0.402 | 0.497 | 0.575 | 0.635 | 0.677 | 0.706 | 0.727 | 0.46 | 0.103 | 0.159 | 0.212 | 0.291 | 0.387 | 0.479 | 0.555 | 0.615 | 0.658 | 0.687 | 0.709 | 0.48 | 0.096 | 0.151 | 0.200 | 0.271 | 0.358 | 0.444 | 0.518 | 0.577 | 0.621 | 0.652 | 0.675 | 0.50 | 0.089 | 0.143 | 0.188 | 0.253 | 0.333 | 0.413 | 0.484 | 0.542 | 0.586 | 0.619 | 0.642 | | | | | | | | | | | | | 0.55 | 0.075 | 0.125 | 0.164 | 0.215 | 0.280 | 0.348 | 0.411 | 0.466 | 0.510 | 0.544 | 0.569 | 0.60 | 0.064 | 0.110 | 0.145 | 0.186 | 0.239 | 0.297 | 0.353 | 0.403 | 0.445 | 0.479 | 0.505 | 0.65 | 0.055 | 0.097 | 0.128 | 0.164 | 0.207 | 0.256 | 0.305 | 0.350 | 0.390 | 0.424 | 0.450 | 0.70 | 0.048 | 0.086 | 0.115 | 0.145 | 0.182 | 0.223 | 0.266 | 0.307 | 0.344 | 0.376 | 0.403 | 0.80 | 0.037 | 0.068 | 0.093 | 0.117 | 0.144 | 0.175 | 0.208 | 0.241 | 0.272 | 0.300 | 0.325 | 0.90 | 0.029 | 0.055 | 0.077 | 0.096 | 0.118 | 0.141 | 0.167 | 0.193 | 0.219 | 0.244 | 0.266 | 1.00 | 0.024 | 0.046 | 0.064 | 0.081 | 0.098 | 0.117 | 0.137 | 0.159 | 0.180 | 0.201 | 0.221 | | | | | | | | | | | | | 1.10 | 0.020 | 0.038 | 0.054 | 0.069 | 0.083 | 0.099 | 0.115 | 0.133 | 0.150 | 0.168 | 0.185 | 1.20 | 0.017 | 0.032 | 0.046 | 0.059 | 0.072 | 0.085 | 0.098 | 0.113 | 0.128 | 0.143 | 0.158 | 1.30 | 0.014 | 0.028 | 0.040 | 0.051 | 0.062 | 0.073 | 0.085 | 0.097 | 0.110 | 0.123 | 0.135 | 1.40 | 0.012 | 0.024 | 0.035 | 0.045 | 0.055 | 0.064 | 0.074 | 0.085 | 0.095 | 0.106 | 0.117 | 1.50 | 0.011 | 0.021 | 0.031 | 0.040 | 0.048 | 0.057 | 0.065 | 0.074 | 0.084 | 0.093 | 0.103 | | | | | | | | | | | | | 1.60 | | 0.019 | 0.028 | 0.035 | 0.043 | 0.051 | 0.058 | 0.066 | 0.074 | 0.083 | 0.092 | 1.70 | | 0.016 | 0.024 | 0.031 | 0.038 | 0.045 | 0.052 | 0.059 | 0.066 | 0.074 | 0.081 | 1.80 | | 0.015 | 0.022 | 0.028 | 0.035 | 0.041 | 0.047 | 0.053 | 0.060 | 0.066 | 0.073 | 1.90 | | 0.013 | 0.019 | 0.026 | 0.031 | 0.037 | 0.043 | 0.048 | 0.054 | 0.060 | 0.065 | 2.00 | | 0.012 | 0.017 | 0.023 | 0.028 | 0.034 | 0.039 | 0.044 | 0.049 | 0.054 | 0.059 |
Element | Mg | Al | Si | P | S | Cl | Ar | K | Ca | Sc | Ti |
---|
Z | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 |
---|
Method | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 5.207 | 5.889 | 5.828 | 5.488 | 5.161 | 4.857 | 4.580 | 8.984 | 9.913 | 9.307 | 8.776 | 0.01 | 5.187 | 5.867 | 5.810 | 5.476 | 5.152 | 4.851 | 4.576 | 8.921 | 9.860 | 9.264 | 8.740 | 0.02 | 5.124 | 5.800 | 5.759 | 5.439 | 5.124 | 4.830 | 4.559 | 8.731 | 9.699 | 9.134 | 8.631 | 0.03 | 5.022 | 5.692 | 5.675 | 5.378 | 5.079 | 4.795 | 4.531 | 8.434 | 9.442 | 8.926 | 8.455 | 0.04 | 4.884 | 5.547 | 5.561 | 5.296 | 5.016 | 4.746 | 4.493 | 8.054 | 9.104 | 8.649 | 8.220 | 0.05 | 4.717 | 5.371 | 5.421 | 5.192 | 4.938 | 4.685 | 4.444 | 7.619 | 8.703 | 8.318 | 7.937 | | | | | | | | | | | | | 0.06 | 4.527 | 5.170 | 5.258 | 5.071 | 4.845 | 4.613 | 4.386 | 7.157 | 8.258 | 7.946 | 7.618 | 0.07 | 4.320 | 4.949 | 5.077 | 4.935 | 4.740 | 4.529 | 4.320 | 6.691 | 7.789 | 7.548 | 7.274 | 0.08 | 4.102 | 4.717 | 4.882 | 4.785 | 4.623 | 4.436 | 4.245 | 6.239 | 7.312 | 7.139 | 6.917 | 0.09 | 3.879 | 4.478 | 4.677 | 4.625 | 4.496 | 4.335 | 4.163 | 5.815 | 6.841 | 6.729 | 6.556 | 0.10 | 3.656 | 4.237 | 4.467 | 4.457 | 4.362 | 4.227 | 4.074 | 5.426 | 6.388 | 6.328 | 6.199 | | | | | | | | | | | | | 0.11 | 3.437 | 3.999 | 4.255 | 4.285 | 4.222 | 4.113 | 3.980 | 5.073 | 5.959 | 5.944 | 5.853 | 0.12 | 3.226 | 3.767 | 4.043 | 4.109 | 4.078 | 3.994 | 3.881 | 4.756 | 5.560 | 5.580 | 5.522 | 0.13 | 3.025 | 3.544 | 3.835 | 3.933 | 3.931 | 3.871 | 3.779 | 4.474 | 5.192 | 5.239 | 5.209 | 0.14 | 2.835 | 3.330 | 3.632 | 3.758 | 3.783 | 3.746 | 3.674 | 4.222 | 4.855 | 4.924 | 4.916 | 0.15 | 2.657 | 3.128 | 3.437 | 3.586 | 3.635 | 3.620 | 3.566 | 3.997 | 4.550 | 4.633 | 4.643 | | | | | | | | | | | | | 0.16 | 2.492 | 2.938 | 3.249 | 3.417 | 3.487 | 3.493 | 3.458 | 3.795 | 4.273 | 4.366 | 4.390 | 0.17 | 2.340 | 2.760 | 3.070 | 3.253 | 3.342 | 3.367 | 3.348 | 3.612 | 4.023 | 4.122 | 4.157 | 0.18 | 2.199 | 2.595 | 2.900 | 3.094 | 3.200 | 3.242 | 3.239 | 3.446 | 3.797 | 3.899 | 3.943 | 0.19 | 2.071 | 2.441 | 2.740 | 2.942 | 3.061 | 3.118 | 3.130 | 3.295 | 3.593 | 3.695 | 3.745 | 0.20 | 1.953 | 2.299 | 2.589 | 2.796 | 2.927 | 2.997 | 3.022 | 3.154 | 3.408 | 3.509 | 3.564 | | | | | | | | | | | | | 0.22 | 1.748 | 2.046 | 2.315 | 2.525 | 2.671 | 2.763 | 2.811 | 2.902 | 3.086 | 3.183 | 3.242 | 0.24 | 1.577 | 1.832 | 2.076 | 2.281 | 2.436 | 2.543 | 2.609 | 2.680 | 2.815 | 2.906 | 2.967 | 0.25 | 1.502 | 1.737 | 1.969 | 2.169 | 2.326 | 2.438 | 2.512 | 2.578 | 2.695 | 2.783 | 2.844 | 0.26 | 1.434 | 1.650 | 1.869 | 2.064 | 2.221 | 2.337 | 2.417 | 2.481 | 2.584 | 2.669 | 2.730 | 0.28 | 1.313 | 1.495 | 1.689 | 1.872 | 2.026 | 2.148 | 2.238 | 2.299 | 2.383 | 2.462 | 2.523 | 0.30 | 1.211 | 1.363 | 1.534 | 1.702 | 1.851 | 1.974 | 2.070 | 2.134 | 2.206 | 2.281 | 2.341 | | | | | | | | | | | | | 0.32 | 1.123 | 1.251 | 1.400 | 1.553 | 1.694 | 1.816 | 1.915 | 1.982 | 2.048 | 2.119 | 2.178 | 0.34 | 1.047 | 1.154 | 1.284 | 1.422 | 1.554 | 1.672 | 1.772 | 1.842 | 1.905 | 1.974 | 2.032 | 0.35 | 1.013 | 1.111 | 1.231 | 1.362 | 1.490 | 1.606 | 1.705 | 1.776 | 1.838 | 1.906 | 1.964 | 0.36 | 0.980 | 1.070 | 1.182 | 1.306 | 1.429 | 1.542 | 1.641 | 1.714 | 1.775 | 1.842 | 1.899 | 0.38 | 0.921 | 0.997 | 1.094 | 1.205 | 1.318 | 1.425 | 1.522 | 1.595 | 1.657 | 1.722 | 1.778 | 0.40 | 0.868 | 0.932 | 1.017 | 1.115 | 1.218 | 1.319 | 1.412 | 1.487 | 1.548 | 1.612 | 1.668 | | | | | | | | | | | | | 0.42 | 0.821 | 0.875 | 0.949 | 1.036 | 1.130 | 1.224 | 1.313 | 1.387 | 1.449 | 1.511 | 1.566 | 0.44 | 0.777 | 0.825 | 0.888 | 0.965 | 1.051 | 1.138 | 1.223 | 1.295 | 1.357 | 1.418 | 1.472 | 0.45 | 0.757 | 0.801 | 0.861 | 0.933 | 1.014 | 1.098 | 1.181 | 1.252 | 1.314 | 1.374 | 1.428 | 0.46 | 0.738 | 0.779 | 0.834 | 0.903 | 0.980 | 1.061 | 1.141 | 1.211 | 1.272 | 1.332 | 1.385 | 0.48 | 0.701 | 0.737 | 0.786 | 0.847 | 0.917 | 0.991 | 1.066 | 1.134 | 1.194 | 1.252 | 1.305 | 0.50 | 0.667 | 0.700 | 0.743 | 0.797 | 0.860 | 0.928 | 0.998 | 1.064 | 1.123 | 1.179 | 1.230 | | | | | | | | | | | | | 0.55 | 0.592 | 0.618 | 0.651 | 0.692 | 0.741 | 0.796 | 0.854 | 0.912 | 0.966 | 1.018 | 1.067 | 0.60 | 0.528 | 0.551 | 0.578 | 0.610 | 0.648 | 0.692 | 0.740 | 0.790 | 0.838 | 0.885 | 0.930 | 0.65 | 0.473 | 0.494 | 0.517 | 0.543 | 0.573 | 0.609 | 0.648 | 0.690 | 0.733 | 0.775 | 0.816 | 0.70 | 0.425 | 0.445 | 0.465 | 0.487 | 0.513 | 0.541 | 0.574 | 0.609 | 0.647 | 0.684 | 0.721 | 0.80 | 0.347 | 0.366 | 0.383 | 0.401 | 0.419 | 0.440 | 0.462 | 0.488 | 0.515 | 0.544 | 0.573 | 0.90 | 0.286 | 0.304 | 0.320 | 0.335 | 0.350 | 0.366 | 0.383 | 0.402 | 0.422 | 0.444 | 0.467 | | | | | | | | | | | | | 1.00 | 0.239 | 0.255 | 0.270 | 0.284 | 0.298 | 0.311 | 0.324 | 0.339 | 0.354 | 0.371 | 0.389 | 1.10 | 0.202 | 0.217 | 0.231 | 0.243 | 0.255 | 0.267 | 0.278 | 0.290 | 0.303 | 0.316 | 0.330 | 1.20 | 0.172 | 0.185 | 0.198 | 0.210 | 0.221 | 0.232 | 0.242 | 0.252 | 0.262 | 0.273 | 0.285 | 1.30 | 0.148 | 0.160 | 0.172 | 0.183 | 0.193 | 0.202 | 0.212 | 0.220 | 0.230 | 0.239 | 0.249 | 1.40 | 0.129 | 0.139 | 0.150 | 0.160 | 0.169 | 0.178 | 0.187 | 0.194 | 0.202 | 0.211 | 0.219 | 1.50 | 0.113 | 0.123 | 0.132 | 0.141 | 0.150 | 0.158 | 0.166 | 0.174 | 0.181 | 0.188 | 0.195 | | | | | | | | | | | | | 1.60 | 0.100 | 0.109 | 0.117 | 0.125 | 0.133 | 0.141 | 0.148 | 0.156 | 0.162 | 0.169 | 0.175 | 1.70 | 0.089 | 0.096 | 0.104 | 0.111 | 0.119 | 0.126 | 0.132 | 0.138 | 0.144 | 0.151 | 0.157 | 1.80 | 0.080 | 0.087 | 0.093 | 0.100 | 0.107 | 0.113 | 0.119 | 0.127 | 0.132 | 0.137 | 0.143 | 1.90 | 0.072 | 0.078 | 0.084 | 0.090 | 0.096 | 0.102 | 0.108 | 0.112 | 0.118 | 0.124 | 0.129 | 2.00 | 0.065 | 0.070 | 0.076 | 0.082 | 0.087 | 0.093 | 0.098 | 0.101 | 0.107 | 0.112 | 0.117 |
Element | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | As |
---|
Z | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 |
---|
Method | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF | RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 8.305 | 6.969 | 7.506 | 7.165 | 6.854 | 6.569 | 5.600 | 6.065 | 7.108 | 7.378 | 7.320 | 0.01 | 8.274 | 6.945 | 7.484 | 7.145 | 6.836 | 6.552 | 5.587 | 6.051 | 7.088 | 7.359 | 7.306 | 0.02 | 8.180 | 6.875 | 7.412 | 7.081 | 6.779 | 6.501 | 5.547 | 6.009 | 7.027 | 7.303 | 7.260 | 0.03 | 8.029 | 6.762 | 7.296 | 6.978 | 6.687 | 6.418 | 5.482 | 5.941 | 6.927 | 7.211 | 7.184 | 0.04 | 7.826 | 6.610 | 7.140 | 6.839 | 6.562 | 6.306 | 5.395 | 5.849 | 6.792 | 7.088 | 7.081 | 0.05 | 7.581 | 6.427 | 6.949 | 6.669 | 6.410 | 6.169 | 5.287 | 5.735 | 6.629 | 6.935 | 6.953 | | | | | | | | | | | | | 0.06 | 7.303 | 6.221 | 6.732 | 6.474 | 6.234 | 6.010 | 5.165 | 5.603 | 6.441 | 6.759 | 6.803 | 0.07 | 7.002 | 5.997 | 6.493 | 6.260 | 6.040 | 5.834 | 5.029 | 5.457 | 6.236 | 6.562 | 6.634 | 0.08 | 6.686 | 5.764 | 6.241 | 6.032 | 5.834 | 5.646 | 4.886 | 5.299 | 6.017 | 6.351 | 6.449 | 0.09 | 6.365 | 5.527 | 5.981 | 5.796 | 5.619 | 5.449 | 4.737 | 5.133 | 5.792 | 6.129 | 6.253 | 0.10 | 6.045 | 5.291 | 5.719 | 5.558 | 5.401 | 5.249 | 4.585 | 4.962 | 5.564 | 5.902 | 6.048 | | | | | | | | | | | | | 0.11 | 5.732 | 5.061 | 5.459 | 5.320 | 5.182 | 5.048 | 4.434 | 4.790 | 5.337 | 5.672 | 5.838 | 0.12 | 5.430 | 4.838 | 5.206 | 5.087 | 4.967 | 4.848 | 4.285 | 4.618 | 5.113 | 5.442 | 5.625 | 0.13 | 5.142 | 4.625 | 4.962 | 4.861 | 4.758 | 4.654 | 4.139 | 4.449 | 4.896 | 5.217 | 5.411 | 0.14 | 4.871 | 4.423 | 4.728 | 4.644 | 4.555 | 4.465 | 3.998 | 4.283 | 4.686 | 4.996 | 5.200 | 0.15 | 4.616 | 4.231 | 4.506 | 4.436 | 4.361 | 4.283 | 3.862 | 4.123 | 4.486 | 4.783 | 4.992 | | | | | | | | | | | | | 0.16 | 4.378 | 4.051 | 4.297 | 4.240 | 4.177 | 4.110 | 3.731 | 3.969 | 4.295 | 4.578 | 4.789 | 0.17 | 4.158 | 3.882 | 4.100 | 4.054 | 4.002 | 3.944 | 3.607 | 3.822 | 4.114 | 4.382 | 4.593 | 0.18 | 3.953 | 3.723 | 3.916 | 3.880 | 3.836 | 3.788 | 3.488 | 3.681 | 3.942 | 4.195 | 4.404 | 0.19 | 3.763 | 3.574 | 3.743 | 3.716 | 3.681 | 3.640 | 3.375 | 3.547 | 3.781 | 4.017 | 4.222 | 0.20 | 3.588 | 3.434 | 3.583 | 3.562 | 3.534 | 3.500 | 3.267 | 3.421 | 3.629 | 3.849 | 4.048 | | | | | | | | | | | | | 0.22 | 3.276 | 3.179 | 3.292 | 3.284 | 3.267 | 3.245 | 3.067 | 3.186 | 3.352 | 3.541 | 3.724 | 0.24 | 3.006 | 2.953 | 3.039 | 3.039 | 3.032 | 3.018 | 2.885 | 2.977 | 3.108 | 3.268 | 3.433 | 0.25 | 2.885 | 2.849 | 2.924 | 2.928 | 2.924 | 2.914 | 2.800 | 2.880 | 2.997 | 3.143 | 3.299 | 0.26 | 2.772 | 2.750 | 2.817 | 2.824 | 2.823 | 2.816 | 2.719 | 2.789 | 2.892 | 3.026 | 3.172 | 0.28 | 2.568 | 2.568 | 2.620 | 2.632 | 2.637 | 2.636 | 2.568 | 2.620 | 2.701 | 2.813 | 2.940 | 0.30 | 2.386 | 2.403 | 2.445 | 2.461 | 1.471 | 2.474 | 2.428 | 2.468 | 2.531 | 2.623 | 2.733 | | | | | | | | | | | | | 0.32 | 2.225 | 2.252 | 2.288 | 2.308 | 2.321 | 2.328 | 2.299 | 2.329 | 2.379 | 2.455 | 2.548 | 0.34 | 2.079 | 2.114 | 2.146 | 2.168 | 2.184 | 2.195 | 2.180 | 2.203 | 2.242 | 2.304 | 2.384 | 0.35 | 2.011 | 2.049 | 2.080 | 2.104 | 2.121 | 2.133 | 2.123 | 2.144 | 2.179 | 2.235 | 2.308 | 0.36 | 1.947 | 1.987 | 2.017 | 2.042 | 2.060 | 2.073 | 2.069 | 2.087 | 2.119 | 2.169 | 2.237 | 0.38 | 1.826 | 1.870 | 1.899 | 1.925 | 1.946 | 1.962 | 1.965 | 1.980 | 2.006 | 2.048 | 2.105 | 0.40 | 1.716 | 1.761 | 1.790 | 1.818 | 1.841 | 1.858 | 1.868 | 1.882 | 1.903 | 1.938 | 1.986 | | | | | | | | | | | | | 0.42 | 1.614 | 1.660 | 1.690 | 1.719 | 1.743 | 1.763 | 1.777 | 1.790 | 1.808 | 1.837 | 1.878 | 0.44 | 1.520 | 1.567 | 1.597 | 1.628 | 1.653 | 1.674 | 1.691 | 1.704 | 1.720 | 1.745 | 1.780 | 0.45 | 1.476 | 1.523 | 1.553 | 1.584 | 1.610 | 1.631 | 1.651 | 1.663 | 1.679 | 1.702 | 1.734 | 0.46 | 1.433 | 1.480 | 1.511 | 1.542 | 1.569 | 1.591 | 1.611 | 1.624 | 1.639 | 1.661 | 1.691 | 0.48 | 1.352 | 1.399 | 1.431 | 1.462 | 1.490 | 1.513 | 1.535 | 1.549 | 1.563 | 1.583 | 1.608 | 0.50 | 1.277 | 1.323 | 1.356 | 1.388 | 1.416 | 1.440 | 1.464 | 1.478 | 1.492 | 1.510 | 1.533 | | | | | | | | | | | | | 0.55 | 1.111 | 1.155 | 1.189 | 1.222 | 1.251 | 1.277 | 1.303 | 1.319 | 1.334 | 1.349 | 1.367 | 0.60 | 0.973 | 1.014 | 1.047 | 1.080 | 1.110 | 1.136 | 1.163 | 1.181 | 1.197 | 1.212 | 1.228 | 0.65 | 0.856 | 0.894 | 0.927 | 0.959 | 0.988 | 1.015 | 1.041 | 1.061 | 1.078 | 1.093 | 1.108 | 0.70 | 0.757 | 0.792 | 0.824 | 0.854 | 0.883 | 0.909 | 0.935 | 0.955 | 0.973 | 0.989 | 1.004 | 0.80 | 0.602 | 0.631 | 0.659 | 0.686 | 0.712 | 0.737 | 0.761 | 0.781 | 0.800 | 0.817 | 0.832 | 0.90 | 0.490 | 0.514 | 0.538 | 0.561 | 0.583 | 0.605 | 0.626 | 0.646 | 0.665 | 0.681 | 0.697 | 1.00 | 0.408 | 0.427 | 0.446 | 0.466 | 0.485 | 0.504 | 0.523 | 0.541 | 0.558 | 0.574 | 0.589 | | | | | | | | | | | | | 1.10 | 0.345 | 0.361 | 0.377 | 0.393 | 0.409 | 0.425 | 0.442 | 0.457 | 0.473 | 0.488 | 0.502 | 1.20 | 0.297 | 0.310 | 0.323 | 0.336 | 0.350 | 0.364 | 0.378 | 0.391 | 0.405 | 0.418 | 0.431 | 1.30 | 0.259 | 0.269 | 0.280 | 0.291 | 0.303 | 0.315 | 0.327 | 0.339 | 0.350 | 0.362 | 0.374 | 1.40 | 0.228 | 0.237 | 0.246 | 0.255 | 0.265 | 0.275 | 0.285 | 0.296 | 0.306 | 0.317 | 0.327 | 1.50 | 0.203 | 0.210 | 0.218 | 0.226 | 0.235 | 0.243 | 0.252 | 0.261 | 0.270 | 0.279 | 0.288 | | | | | | | | | | | | | 1.60 | 0.182 | 0.188 | 0.195 | 0.202 | 0.209 | 0.217 | 0.224 | 0.232 | 0.240 | 0.248 | 0.256 | 1.70 | 0.163 | 0.169 | 0.175 | 0.181 | 0.188 | 0.194 | 0.201 | 0.208 | 0.215 | 0.222 | 0.229 | 1.80 | 0.148 | 0.154 | 0.159 | 0.165 | 0.170 | 1.176 | 0.182 | 0.188 | 0.194 | 0.200 | 0.206 | 1.90 | 0.134 | 0.139 | 0.144 | 0.149 | 0.154 | 0.160 | 0.165 | 0.170 | 0.175 | 0.181 | 0.187 | 2.00 | 0.122 | 0.127 | 0.132 | 0.136 | 0.141 | 0.146 | 0.150 | 0.155 | 0.160 | 0.165 | 0.170 |
Element | Se | Br | Kr | Rb | Sr | Y | Zr | Nb | Mo | Tc | Ru |
---|
Z | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 |
---|
Method | RHF | RHF | RHF | RHF | RHF | *RHF | *RHF | *RHF | *RHF | *RHF | *RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 7.205 | 7.060 | 6.897 | 11.778 | 13.109 | 12.674 | 12.166 | 10.679 | 10.260 | 10.856 | 9.558 | 0.01 | 7.192 | 7.049 | 6.889 | 11.699 | 13.035 | | | | 10.230 | | | 0.02 | 7.154 | 7.016 | 6.861 | 11.460 | 12.816 | | | | 10.138 | | | 0.03 | 7.090 | 6.962 | 6.814 | 11.088 | 12.468 | | | | 9.989 | | | 0.04 | 7.004 | 6.888 | 6.750 | 10.613 | 12.013 | 11.79 | 11.41 | 10.13 | 9.790 | 10.35 | 9.18 | 0.05 | 6.895 | 6.795 | 6.670 | 10.073 | 11.476 | 11.34 | 11.04 | 9.86 | 9.548 | 10.10 | 8.99 | | | | | | | | | | | | | 0.06 | 6.767 | 6.684 | 6.574 | 9.504 | 10.888 | 10.84 | 10.62 | 9.54 | 9.272 | 9.80 | 8.77 | 0.07 | 6.621 | 6.558 | 6.464 | 8.934 | 10.273 | 10.31 | 10.15 | 9.20 | 8.972 | 9.48 | 8.53 | 0.08 | 6.460 | 6.418 | 6.341 | 8.385 | 9.655 | 9.77 | 9.68 | 8.85 | 8.655 | 9.14 | 8.27 | 0.09 | 6.288 | 6.266 | 6.207 | 7.872 | 9.052 | 9.23 | 9.20 | 8.49 | 8.330 | 8.78 | 8.00 | 0.10 | 6.105 | 6.104 | 6.064 | 7.402 | 8.478 | 8.70 | 8.72 | 8.12 | 8.004 | 8.42 | 7.73 | | | | | | | | | | | | | 0.11 | 5.916 | 5.935 | 5.913 | 6.976 | 7.940 | 8.20 | 8.26 | 7.77 | 7.680 | 8.07 | 7.46 | 0.12 | 5.722 | 5.760 | 5.755 | 6.593 | 7.443 | 7.722 | 7.818 | 7.421 | 7.364 | 7.720 | 7.190 | 0.13 | 5.525 | 5.580 | 5.593 | 6.248 | 6.988 | 7.278 | 7.400 | 7.090 | 7.058 | 7.383 | 6.928 | 0.14 | 5.328 | 5.399 | 5.428 | 5.938 | 6.575 | 6.865 | 7.007 | 6.772 | 6.763 | 7.057 | 6.672 | 0.15 | 5.132 | 5.217 | 5.260 | 5.658 | 6.200 | 6.485 | 6.640 | 6.472 | 6.481 | 6.746 | 6.426 | | | | | | | | | | | | | 0.16 | 4.938 | 5.036 | 5.092 | 5.403 | 5.862 | 6.136 | 6.299 | 6.187 | 6.213 | 6.451 | 6.188 | 0.17 | 4.749 | 4.857 | 4.925 | 5.170 | 5.555 | 5.816 | 5.983 | 5.918 | 5.957 | 6.171 | 5.960 | 0.18 | 4.564 | 4.680 | 4.759 | 4.954 | 5.278 | 5.523 | 5.689 | 5.665 | 5.715 | 5.907 | 5.741 | 0.19 | 4.384 | 4.507 | 4.595 | 4.754 | 5.025 | 5.254 | 5.419 | 5.427 | 5.486 | 5.658 | 5.533 | 0.20 | 4.211 | 4.339 | 4.434 | 4.566 | 4.794 | 5.008 | 5.168 | 5.203 | 5.269 | 5.423 | 5.332 | | | | | | | | | | | | | 0.22 | 3.884 | 4.017 | 4.123 | 4.224 | 4.387 | 4.570 | 4.721 | 4.792 | 4.868 | 4.994 | 4.959 | 0.24 | 3.585 | 3.718 | 3.829 | 3.916 | 4.039 | 4.195 | 4.333 | 4.426 | 4.507 | 4.614 | 4.618 | 0.25 | 3.446 | 3.578 | 3.690 | 3.773 | 3.882 | 4.027 | 4.158 | 4.258 | 4.341 | 4.439 | 4.459 | 0.26 | 3.314 | 3.443 | 3.556 | 3.636 | 3.735 | 3.869 | 3.995 | 4.099 | 4.182 | 4.273 | 4.306 | 0.28 | 3.069 | 3.192 | 3.303 | 3.382 | 3.465 | 3.583 | 3.697 | 3.804 | 3.888 | 3.969 | 4.021 | 0.30 | 2.849 | 2.963 | 3.071 | 3.149 | 3.224 | 3.329 | 3.433 | 3.539 | 3.622 | 3.695 | 3.759 | | | | | | | | | | | | | 0.32 | 2.651 | 2.757 | 2.858 | 2.936 | 3.007 | 3.101 | 3.196 | 3.298 | 3.379 | 3.448 | 3.518 | 0.34 | 2.475 | 2.570 | 2.665 | 2.742 | 2.810 | 2.895 | 2.982 | 3.080 | 3.158 | 3.223 | 3.296 | 0.35 | 2.393 | 2.484 | 2.575 | 2.651 | 2.718 | 2.799 | 2.883 | 2.978 | 3.054 | 3.118 | 3.192 | 0.36 | 2.316 | 2.402 | 2.490 | 2.564 | 2.630 | 2.708 | 2.789 | 2.880 | 2.955 | 3.018 | 3.092 | 0.38 | 2.173 | 2.250 | 2.330 | 2.402 | 2.466 | 2.538 | 2.613 | 2.698 | 2.770 | 2.830 | 2.904 | 0.40 | 2.045 | 2.113 | 2.186 | 2.254 | 2.315 | 2.383 | 2.452 | 2.531 | 2.600 | 2.658 | 2.730 | | | | | | | | | | | | | 0.42 | 1.929 | 1.989 | 2.055 | 2.119 | 2.178 | 2.241 | 2.305 | 2.379 | 2.444 | 2.500 | 2.570 | 0.44 | 1.824 | 1.877 | 1.936 | 1.995 | 2.052 | 2.111 | 2.171 | 2.239 | 2.300 | 2.355 | 2.421 | 0.45 | 1.776 | 1.825 | 1.881 | 1.938 | 1.993 | 2.049 | 2.108 | 2.173 | 2.233 | 2.287 | 2.351 | 0.46 | 1.729 | 1.775 | 1.828 | 1.883 | 1.936 | 1.991 | 2.047 | 2.110 | 2.168 | 2.221 | 2.284 | 0.48 | 1.642 | 1.683 | 1.730 | 1.780 | 1.830 | 1.881 | 1.934 | 1.991 | 2.046 | 2.098 | 2.157 | 0.50 | 1.562 | 1.598 | 1.640 | 1.686 | 1.733 | 1.780 | 1.829 | 1.883 | 1.934 | 1.984 | 2.040 | | | | | | | | | | | | | 0.55 | 1.389 | 1.416 | 1.447 | 1.483 | 1.522 | 1.562 | 1.603 | 1.646 | 1.690 | 1.734 | 1.782 | 0.60 | 1.245 | 1.266 | 1.290 | 1.319 | 1.350 | 1.383 | 1.417 | 1.452 | 1.490 | 1.528 | 1.569 | 0.65 | 1.124 | 1.141 | 1.160 | 1.182 | 1.208 | 1.235 | 1.263 | 1.292 | 1.324 | 1.357 | 1.391 | 0.70 | 1.019 | 1.034 | 1.050 | 1.068 | 1.089 | 1.111 | 1.135 | 1.159 | 1.185 | 1.214 | 1.243 | 0.80 | 0.847 | 0.860 | 0.873 | 0.887 | 0.902 | 0.918 | 0.935 | 0.952 | 0.971 | 0.992 | 1.013 | 0.90 | 0.711 | 0.725 | 0.737 | 0.749 | 0.762 | 0.774 | 0.787 | 0.800 | 0.814 | 0.830 | 0.845 | 1.00 | 0.603 | 0.616 | 0.628 | 0.640 | 0.651 | 0.662 | 0.673 | 0.684 | 0.695 | 0.707 | 0.719 | | | | | | | | | | | | | 1.10 | 0.515 | 0.528 | 0.540 | 0.551 | 0.562 | 0.572 | 0.582 | 0.591 | 0.601 | 0.611 | 0.621 | 1.20 | 0.444 | 0.456 | 0.467 | 0.478 | 0.488 | 0.498 | 0.507 | 0.516 | 0.525 | 0.534 | 0.542 | 1.30 | 0.385 | 0.396 | 0.407 | 0.417 | 0.427 | 0.436 | 0.445 | 0.454 | 0.462 | 0.470 | 0.478 | 1.40 | 0.337 | 0.347 | 0.357 | 0.365 | 0.375 | 0.384 | 0.393 | 0.401 | 0.408 | 0.416 | 0.423 | 1.50 | 0.297 | 0.306 | 0.315 | 0.325 | 0.333 | 0.341 | 0.349 | 0.356 | 0.364 | 0.371 | 0.378 | | | | | | | | | | | | | 1.60 | 0.264 | 0.272 | 0.280 | 0.290 | 0.297 | 0.303 | 0.311 | 0.318 | 0.325 | 0.332 | 0.338 | 1.70 | 0.236 | 0.243 | 0.250 | 0.257 | 0.264 | 0.272 | 0.278 | 0.285 | 0.291 | 0.298 | 0.304 | 1.80 | 0.212 | 0.219 | 0.225 | 0.233 | 0.239 | 0.244 | 0.251 | 0.257 | 0.263 | 0.269 | 0.275 | 1.90 | 0.192 | 0.198 | 0.204 | 0.208 | 0.214 | 0.221 | 0.227 | 0.233 | 0.238 | 0.244 | 0.249 | 2.00 | 0.175 | 0.180 | 0.185 | 0.188 | 0.194 | 0.201 | 0.206 | 0.211 | 0.216 | 0.222 | 0.227 |
Element | Rh | Pd | Ag | Cd | In | Sn | Sb | Te | I | Xe | Cs |
---|
Z | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 |
---|
Method | *RHF | *RHF | RHF | RHF | RHF | RHF | RHF | *RHF | RHF | RHF | RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 9.242 | 7.583 | 8.671 | 9.232 | 10.434 | 10.859 | 10.974 | 11.003 | 10.905 | 10.794 | 16.508 | 0.01 | | | 8.654 | 9.213 | 10.406 | 10.833 | 10.950 | | 10.887 | 10.777 | 16.391 | 0.02 | | | 8.599 | 9.153 | 10.320 | 10.750 | 10.876 | | 10.828 | 10.725 | 16.050 | 0.03 | | | 8.510 | 9.057 | 10.181 | 10.615 | 10.755 | | 10.731 | 10.638 | 15.521 | 0.04 | 8.90 | 7.43 | 8.391 | 8.926 | 9.995 | 10.433 | 10.591 | 10.65 | 10.599 | 10.520 | 14.855 | 0.05 | 8.73 | 7.35 | 8.244 | 8.764 | 9.768 | 10.209 | 10.387 | 10.47 | 10.434 | 10.371 | 14.106 | | | | | | | | | | | | | 0.06 | 8.53 | 7.26 | 8.075 | 8.577 | 9.509 | 9.950 | 10.150 | 10.25 | 10.238 | 10.194 | 13.326 | 0.07 | 8.31 | 7.16 | 7.888 | 8.369 | 9.224 | 9.664 | 9.884 | 10.01 | 10.017 | 9.993 | 12.556 | 0.08 | 8.01 | 7.03 | 7.689 | 8.144 | 8.923 | 9.357 | 9.596 | 9.74 | 9.773 | 9.771 | 11.823 | 0.09 | 7.83 | 6.91 | 7.480 | 7.909 | 8.612 | 9.037 | 9.291 | 9.46 | 9.511 | 9.530 | 11.145 | 0.10 | 7.58 | 6.77 | 7.267 | 7.666 | 8.297 | 8.709 | 8.976 | 9.16 | 9.235 | 9.274 | 10.525 | | | | | | | | | | | | | 0.11 | 7.33 | 6.62 | 7.052 | 7.421 | 7.983 | 8.380 | 8.654 | 8.85 | 8.948 | 9.007 | 9.965 | 0.12 | 7.079 | 6.474 | 6.837 | 7.176 | 7.674 | 8.053 | 8.331 | 8.538 | 8.654 | 8.732 | 9.458 | 0.13 | 6.836 | 6.319 | 6.625 | 6.933 | 7.374 | 7.732 | 8.010 | 8.224 | 8.357 | 8.451 | 9.000 | 0.14 | 6.598 | 6.162 | 6.418 | 6.695 | 7.084 | 7.419 | 7.694 | 7.914 | 8.059 | 8.167 | 8.583 | 0.15 | 6.366 | 6.003 | 6.215 | 6.464 | 6.805 | 7.118 | 7.386 | 7.608 | 7.764 | 7.884 | 8.201 | | | | | | | | | | | | | 0.16 | 6.143 | 5.843 | 6.018 | 6.240 | 6.539 | 6.829 | 7.088 | 7.309 | 7.472 | 7.603 | 7.848 | 0.17 | 5.929 | 5.684 | 5.827 | 6.024 | 6.286 | 6.552 | 6.800 | 7.018 | 7.186 | 7.325 | 7.519 | 0.18 | 5.722 | 5.526 | 5.643 | 5.817 | 6.045 | 6.289 | 6.524 | 6.738 | 6.908 | 7.053 | 7.212 | 0.19 | 5.524 | 5.369 | 5.464 | 5.618 | 5.817 | 6.039 | 6.261 | 6.467 | 6.639 | 6.787 | 6.922 | 0.20 | 5.334 | 5.214 | 5.293 | 5.427 | 5.601 | 5.803 | 6.010 | 6.209 | 6.379 | 6.529 | 6.649 | | | | | | | | | | | | | 0.22 | 4.976 | 4.913 | 4.967 | 5.070 | 5.203 | 5.368 | 5.547 | 5.727 | 5.889 | 6.039 | 6.143 | 0.24 | 4.648 | 4.626 | 4.665 | 4.745 | 4.846 | 4.979 | 5.131 | 3.291 | 5.442 | 5.586 | 5.684 | 0.25 | 4.493 | 4.487 | 4.522 | 4.592 | 4.682 | 4.801 | 4.940 | 5.090 | 5.234 | 5.374 | 5.471 | 0.26 | 4.345 | 4.352 | 4.384 | 4.447 | 4.525 | 4.633 | 4.760 | 4.899 | 5.036 | 5.172 | 5.268 | 0.28 | 4.066 | 4.093 | 4.122 | 4.173 | 4.236 | 4.323 | 4.428 | 4.548 | 4.670 | 4.795 | 4.890 | 0.30 | 3.809 | 3.850 | 3.878 | 3.922 | 3.973 | 4.044 | 4.131 | 4.234 | 4.341 | 4.454 | 4.547 | | | | | | | | | | | | | 0.32 | 3.572 | 3.622 | 3.651 | 3.690 | 3.734 | 3.792 | 3.865 | 3.952 | 4.046 | 4.147 | 4.235 | 0.34 | 3.353 | 3.408 | 3.440 | 3.476 | 3.515 | 3.564 | 3.625 | 3.700 | 3.780 | 3.870 | 3.953 | 0.35 | 3.249 | 3.306 | 3.339 | 3.375 | 3.412 | 3.458 | 3.514 | 3.583 | 3.658 | 3.742 | 3.822 | 0.36 | 3.150 | 3.208 | 3.242 | 3.278 | 3.313 | 3.356 | 3.408 | 3.472 | 3.541 | 3.620 | 3.697 | 0.38 | 2.962 | 3.022 | 3.058 | 3.093 | 3.127 | 3.165 | 3.210 | 3.265 | 3.325 | 3.394 | 3.465 | 0.40 | 2.788 | 2.848 | 2.886 | 2.922 | 2.955 | 2.990 | 3.030 | 3.078 | 3.130 | 3.191 | 3.255 | | | | | | | | | | | | | 0.42 | 2.626 | 2.686 | 2.726 | 2.762 | 2.795 | 2.828 | 2.864 | 2.907 | 2.953 | 3.006 | 3.064 | 0.44 | 2.477 | 2.535 | 2.576 | 2.613 | 2.646 | 2.678 | 2.712 | 2.750 | 2.791 | 2.838 | 2.890 | 0.45 | 2.406 | 2.464 | 2.505 | 2.542 | 2.576 | 2.608 | 2.640 | 2.677 | 2.715 | 2.759 | 2.809 | 0.46 | 2.338 | 2.395 | 2.436 | 2.474 | 2.507 | 2.539 | 2.571 | 2.606 | 2.642 | 2.684 | 2.731 | 0.48 | 2.210 | 2.264 | 2.306 | 2.344 | 2.378 | 2.409 | 2.440 | 2.473 | 2.506 | 2.543 | 2.586 | 0.50 | 2.090 | 2.143 | 2.185 | 2.223 | 2.257 | 2.288 | 2.318 | 2.350 | 2.380 | 2.414 | 2.453 | | | | | | | | | | | | | 0.55 | 1.828 | 1.875 | 1.915 | 1.953 | 1.987 | 2.019 | 2.048 | 2.077 | 2.104 | 2.132 | 2.163 | 0.60 | 1.609 | 1.650 | 1.688 | 1.724 | 1.758 | 1.790 | 1.819 | 1.847 | 1.871 | 1.897 | 1.923 | 0.65 | 1.426 | 1.462 | 1.497 | 1.531 | 1.563 | 1.594 | 1.622 | 1.649 | 1.673 | 1.697 | 1.721 | 0.70 | 1.273 | 1.304 | 1.335 | 1.366 | 1.397 | 1.426 | 1.453 | 1.479 | 1.503 | 1.526 | 1.548 | 0.80 | 1.035 | 1.058 | 1.082 | 1.107 | 1.132 | 1.157 | 1.181 | 1.205 | 1.227 | 1.248 | 1.269 | 0.90 | 0.861 | 0.879 | 0.897 | 0.916 | 0.936 | 0.956 | 0.976 | 0.997 | 1.016 | 1.036 | 1.055 | 1.00 | 0.731 | 0.745 | 0.758 | 0.773 | 0.789 | 0.805 | 0.821 | 0.838 | 0.855 | 0.871 | 0.888 | | | | | | | | | | | | | 1.10 | 0.631 | 0.641 | 0.652 | 0.664 | 0.676 | 0.688 | 0.701 | 0.715 | 0.729 | 0.743 | 0.758 | 1.20 | 0.551 | 0.559 | 0.568 | 0.578 | 0.587 | 0.597 | 0.608 | 0.619 | 0.630 | 0.642 | 0.654 | 1.30 | 0.485 | 0.493 | 0.500 | 0.508 | 0.516 | 0.525 | 0.533 | 0.542 | 0.551 | 0.561 | 0.570 | 1.40 | 0.431 | 0.437 | 0.444 | 0.451 | 0.458 | 0.465 | 0.472 | 0.480 | 0.487 | 0.495 | 0.502 | 1.50 | 0.384 | 0.391 | 0.397 | 0.403 | 0.409 | 0.416 | 0.422 | 0.428 | 0.435 | 0.442 | 0.450 | | | | | | | | | | | | | 1.60 | 0.345 | 0.351 | 0.357 | 0.362 | 0.368 | 0.374 | 0.379 | 0.385 | 0.391 | 0.397 | 0.405 | 1.70 | 0.310 | 0.316 | 0.321 | 0.327 | 0.332 | 0.337 | 0.343 | 0.348 | 0.353 | 0.358 | 0.363 | 1.80 | 0.281 | 0.286 | 0.291 | 0.297 | 0.302 | 0.307 | 0.311 | 0.316 | 0.321 | 0.325 | 0.332 | 1.90 | 0.255 | 0.260 | 0.265 | 0.270 | 0.274 | 0.279 | 0.284 | 0.288 | 0.293 | 0.297 | 0.299 | 2.00 | 0.232 | 0.237 | 0.241 | 0.246 | 0.250 | 0.255 | 0.259 | 0.264 | 0.268 | 0.272 | 0.272 |
Element | Ba | La | Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy |
---|
Z | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 |
---|
Method | RHF | *RHF | *RHF | *RMF | *RHF | *RHF | *RHF | RHF | *RHF | *RHF | *RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 18.267 | 17.805 | 17.378 | 16.987 | 16.606 | 16.243 | 15.897 | 15.563 | 15.266 | 14.974 | 14.641 | 0.01 | 18.157 | | | | | | | 15.486 | | | | 0.02 | 17.828 | | | | | | | 15.260 | | | | 0.03 | 17.309 | | | | | | | 14.898 | | | | 0.04 | 16.636 | 16.45 | 16.10 | 15.62 | 15.30 | 14.99 | 14.70 | 14.425 | 14.30 | 13.90 | 13.64 | 0.05 | 15.854 | 15.79 | 15.46 | 14.94 | 14.67 | 14.39 | 14.12 | 13.867 | 13.81 | 13.37 | 13.14 | | | | | | | | | | | | | 0.06 | 15.008 | 15.05 | 14.77 | 14.22 | 13.97 | 13.72 | 13.48 | 13.253 | 13.27 | 12.81 | 12.60 | 0.07 | 14.138 | 14.28 | 14.03 | 13.47 | 13.25 | 13.03 | 12.81 | 12.611 | 12.70 | 12.22 | 12.03 | 0.08 | 13.278 | 13.51 | 13.29 | 12.72 | 12.52 | 12.33 | 12.14 | 11.963 | 12.11 | 11.62 | 11.44 | 0.09 | 12.431 | 12.74 | 12.56 | 11.99 | 11.82 | 11.65 | 11.49 | 11.329 | 11.52 | 11.02 | 10.87 | 0.10 | 11.675 | 12.01 | 11.85 | 11.29 | 11.15 | 11.00 | 10.86 | 10.722 | 10.95 | 10.45 | 10.32 | | | | | | | | | | | | | 0.11 | 10.958 | 11.32 | 11.19 | 10.65 | 10.52 | 10.40 | 10.27 | 10.150 | 10.39 | 9.91 | 9.79 | 0.12 | 10.302 | 10.671 | 10.561 | 10.052 | 9.944 | 9.833 | 9.722 | 9.618 | 9.871 | 9.407 | 9.303 | 0.13 | 9.707 | 10.072 | 9.981 | 9.506 | 9.412 | 9.316 | 9.218 | 9.128 | 9.382 | 8.942 | 8.848 | 0.14 | 9.168 | 9.522 | 9.448 | 9.008 | 8.928 | 8.843 | 8.758 | 8.678 | 8.926 | 8.512 | 8.429 | 0.15 | 8.682 | 9.017 | 8.958 | 8.556 | 8.486 | 8.413 | 8.336 | 8.267 | 8.505 | 8.121 | 8.045 | | | | | | | | | | | | | 0.16 | 8.241 | 8.555 | 8.507 | 8.144 | 8.084 | 8.020 | 7.953 | 7.891 | 8.114 | 7.761 | 7.693 | 0.17 | 7.840 | 8.131 | 8.094 | 7.768 | 7.717 | 7.661 | 7.602 | 7.548 | 7.754 | 7.430 | 7.370 | 0.18 | 7.474 | 7.742 | 7.714 | 7.424 | 7.380 | 7.332 | 7.280 | 7.232 | 7.422 | 7.128 | 7.073 | 0.19 | 7.139 | 7.384 | 7.365 | 7.107 | 7.071 | 7.029 | 6.983 | 6.942 | 7.114 | 6.849 | 6.800 | 0.20 | 6.829 | 7.053 | 7.041 | 6.815 | 6.785 | 6.749 | 6.710 | 6.673 | 6.828 | 6.591 | 6.547 | | | | | | | | | | | | | 0.22 | 6.275 | 6.462 | 6.462 | 6.291 | 6.272 | 6.247 | 6.218 | 6.191 | 6.316 | 6.127 | 6.092 | 0.24 | 5.791 | 5.948 | 5.957 | 5.831 | 5.822 | 5.806 | 5.787 | 5.768 | 5.868 | 5.720 | 5.693 | 0.25 | 5.570 | 5.714 | 5.728 | 5.620 | 5.615 | 5.605 | 5.589 | 5.574 | 5.664 | 5.534 | 5.510 | 0.26 | 5.361 | 5.495 | 5.312 | 5.421 | 5.421 | 5.413 | 5.402 | 5.390 | 5.472 | 5.358 | 5.337 | 0.28 | 4.975 | 5.092 | 5.115 | 5.053 | 5.059 | 5.059 | 5.055 | 5.030 | 5.117 | 5.030 | 5.016 | 0.30 | 4.628 | 4.730 | 4.759 | 4.719 | 4.731 | 4.737 | 4.739 | 4.740 | 4.796 | 4.731 | 4.723 | | | | | | | | | | | | | 0.32 | 4.313 | 4.405 | 4.438 | 4.414 | 4.432 | 4.443 | 4.450 | 4.456 | 4.504 | 4.457 | 4.454 | 0.34 | 4.028 | 4.111 | 4.146 | 4.136 | 4.157 | 4.173 | 4.185 | 4.195 | 4.238 | 4.205 | 4.206 | 0.35 | 3.893 | 3.974 | 4.010 | 4.006 | 4.029 | 4.047 | 4.060 | 4.072 | 4.113 | 4.086 | 4.089 | 0.36 | 3.769 | 3.844 | 3.881 | 3.882 | 3.906 | 3.925 | 3.940 | 3.954 | 3.993 | 3.971 | 3.976 | 0.38 | 3.533 | 3.602 | 3.640 | 3.648 | 3.675 | 3.697 | 3.715 | 3.731 | 3.767 | 3.755 | 3.763 | 0.40 | 3.318 | 3.381 | 3.420 | 3.434 | 3.462 | 3.486 | 3.306 | 3.525 | 3.559 | 3.554 | 3.565 | | | | | | | | | | | | | 0.42 | 3.123 | 3.180 | 3.219 | 3.238 | 3.267 | 3.292 | 3.314 | 3.335 | 3.367 | 3.368 | 3.380 | 0.44 | 2.944 | 2.997 | 3.035 | 3.057 | 3.087 | 3.114 | 3.137 | 3.159 | 3.189 | 3.194 | 3.209 | 0.43 | 2.861 | 2.911 | 2.949 | 2.973 | 3.003 | 3.029 | 3.053 | 3.075 | 3.105 | 3.113 | 3.128 | 0.46 | 2.781 | 2.829 | 2.866 | 2.891 | 2.922 | 2.948 | 2.973 | 2.995 | 3.025 | 3.034 | 3.050 | 0.48 | 2.631 | 2.676 | 2.712 | 2.739 | 2.769 | 2.796 | 2.821 | 2.844 | 2.872 | 2.884 | 2.901 | 0.50 | 2.494 | 2.535 | 2.570 | 2.598 | 2.628 | 2.655 | 2.680 | 2.703 | 2.730 | 2.745 | 2.763 | | | | | | | | | | | | | 0.55 | 2.197 | 2.230 | 2.262 | 2.291 | 2.320 | 2.346 | 2.371 | 2.394 | 2.419 | 2.457 | 2.456 | 0.60 | 1.951 | 1.979 | 2.008 | 2.037 | 2.064 | 2.089 | 2.113 | 2.156 | 2.138 | 2.178 | 2.197 | 0.65 | 1.745 | 1.770 | 1.796 | 1.824 | 1.849 | 1.872 | 1.895 | 1.917 | 1.937 | 1.958 | 1.977 | 0.70 | 1.570 | 1.592 | 1.617 | 1.643 | 1.666 | 1.688 | 1.709 | 1.730 | 1.749 | 1.770 | 1.788 | 0.80 | 1.288 | 1.308 | 1.329 | 1.351 | 1.372 | 1.391 | 1.411 | 1.429 | 1.446 | 1.465 | 1.482 | 0.90 | 1.073 | 1.090 | 1.109 | 1.128 | 1.146 | 1.164 | 1.181 | 1.198 | 1.213 | 1.231 | 1.246 | 1.00 | 0.904 | 0.920 | 0.936 | 0.953 | 0.969 | 0.985 | 1.000 | 1.016 | 1.030 | 1.045 | 1.060 | | | | | | | | | | | | | 1.10 | 0.772 | 0.785 | 0.799 | 0.814 | 0.828 | 0.842 | 0.856 | 0.870 | 0.883 | 0.897 | 0.910 | 1.20 | 0.666 | 0.678 | 0.690 | 0.702 | 0.715 | 0.727 | 0.739 | 0.752 | 0.763 | 0.776 | 0.787 | 1.30 | 0.580 | 0.391 | 0.602 | 0.612 | 0.623 | 0.634 | 0.644 | 0.655 | 0.666 | 0.676 | 0.687 | 1.40 | 0.511 | 0.521 | 0.530 | 0.539 | 0.548 | 0.557 | 0.566 | 0.575 | 0.383 | 0.595 | 0.604 | 1.50 | 0.436 | 0.463 | 0.470 | 0.478 | 0.486 | 0.494 | 0.502 | 0.511 | 0.519 | 0.527 | 0.535 | | | | | | | | | | | | | 1.60 | 0.411 | 0.415 | 0.421 | 0.428 | 0.435 | 0.442 | 0.449 | 0.457 | 0.463 | 0.470 | 0.478 | 1.70 | 0.367 | 0.374 | 0.380 | 0.386 | 0.392 | 0.398 | 0.404 | 0.409 | 0.416 | 0.423 | 0.429 | 1.80 | 0.337 | 0.340 | 0.345 | 0.350 | 0.355 | 0.360 | 0.366 | 0.372 | 0.377 | 0.382 | 0.388 | 1.90 | 0.304 | 0.310 | 0.314 | 0.319 | 0.324 | 0.328 | 0.333 | 0.337 | 0.343 | 0.348 | 0.353 | 2.00 | 0.277 | 0.284 | 0.288 | 0.292 | 0.296 | 0.301 | 0.305 | 0.307 | 0.313 | 0.318 | 0.322 |
Element | Ho | Er | Tm | Yb | Lu | Hf | Ta | W | Re | Os | Ir |
---|
Z | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 |
---|
Method | *RHF | *RHF | *RHF | *RHF | *RHF | *RHF | *RHF | *RHF | *RHF | *RHF | *RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 14.355 | 14.080 | 13.814 | 13.557 | 13.486 | 13.177 | 12.856 | 12.543 | 12.263 | 11.987 | 11.718 | 0.01 | | | | | | | | | | | | 0.02 | | | | | | | | | | | | 0.03 | | | | | | | | | | | | 0.04 | 13.57 | 13.16 | 12.92 | 12.70 | 12.74 | 12.55 | 12.31 | 12.06 | 11.83 | 11.59 | 11.37 | 0.05 | 13.14 | 12.70 | 12.48 | 12.28 | 12.38 | 12.23 | 12.01 | 11.80 | 11.60 | 11.39 | 11.18 | | | | | | | | | | | | | 0.06 | 12.66 | 12.19 | 12.00 | 11.81 | 11.95 | 11.85 | 11.69 | 11.51 | 11.34 | 11.15 | 10.96 | 0.07 | 12.15 | 11.66 | 11.48 | 11.31 | 11.50 | 11.45 | 11.33 | 11.18 | 11.04 | 10.88 | 10.72 | 0.08 | 11.61 | 11.11 | 10.96 | 10.80 | 11.03 | 11.02 | 10.95 | 10.83 | 10.73 | 10.59 | 10.45 | 0.09 | 11.08 | 10.58 | 10.44 | 10.29 | 10.55 | 10.59 | 10.55 | 10.47 | 10.40 | 10.29 | 10.17 | 0.10 | 10.55 | 10.06 | 9.93 | 9.80 | 10.08 | 10.16 | 10.15 | 10.10 | 10.05 | 9.98 | 9.88 | | | | | | | | | | | | | 0.11 | 10.05 | 9.56 | 9.45 | 9.33 | 9.62 | 9.73 | 9.75 | 9.74 | 9.71 | 9.65 | 9.58 | 0.12 | 9.562 | 9.095 | 8.994 | 8.892 | 9.180 | 9.308 | 9.363 | 9.369 | 9.366 | 9.334 | 9.281 | 0.13 | 9.108 | 8.662 | 8.571 | 8.480 | 8.762 | 8.907 | 8.982 | 9.011 | 9.028 | 9.016 | 8.982 | 0.14 | 8.681 | 8.262 | 8.180 | 8.098 | 8.370 | 8.525 | 8.616 | 8.663 | 8.697 | 8.702 | 8.686 | 0.15 | 8.284 | 7.895 | 7.821 | 7.746 | 8.001 | 8.163 | 8.266 | 8.327 | 8.376 | 8.396 | 8.395 | | | | | | | | | | | | | 0.16 | 7.917 | 7.557 | 7.490 | 7.421 | 7.660 | 7.822 | 7.933 | 8.006 | 8.067 | 8.099 | 8.111 | 0.17 | 7.577 | 7.247 | 7.185 | 7.123 | 7.343 | 7.502 | 7.617 | 7.699 | 7.769 | 7.813 | 7.836 | 0.18 | 7.262 | 6.962 | 6.905 | 6.849 | 7.047 | 7.202 | 7.321 | 7.408 | 7.485 | 7.537 | 7.570 | 0.19 | 6.971 | 6.698 | 6.646 | 6.595 | 6.774 | 6.922 | 7.040 | 7.132 | 7.213 | 7.272 | 7.313 | 0.20 | 6.700 | 6.454 | 6.407 | 6.360 | 6.520 | 6.660 | 6.776 | 6.870 | 6.954 | 7.019 | 7.067 | | | | | | | | | | | | | 0.22 | 6.213 | 6.017 | 5.978 | 5.938 | 6.063 | 6.185 | 6.295 | 6.388 | 6.475 | 6.547 | 6.604 | 0.24 | 5.788 | 5.632 | 5.601 | 5.568 | 5.664 | 5.768 | 5.867 | 5.957 | 6.043 | 6.117 | 6.180 | 0.25 | 5.595 | 5.457 | 5.428 | 5.398 | 5.483 | 5.578 | 5.672 | 5.759 | 5.843 | 5.917 | 5.982 | 0.26 | 5.412 | 5.290 | 5.265 | 5.238 | 5.312 | 5.399 | 5.487 | 5.571 | 5.653 | 5.727 | 5.792 | 0.28 | 5.075 | 4.981 | 4.961 | 4.940 | 4.996 | 5.069 | 5.147 | 5.224 | 5.301 | 5.372 | 5.437 | 0.30 | 4.771 | 4.699 | 4.685 | 4.669 | 4.712 | 4.772 | 4.840 | 4.910 | 4.981 | 5.049 | 5.113 | | | | | | | | | | | | | 0.32 | 4.494 | 4.440 | 4.430 | 4.419 | 4.453 | 4.503 | 4.563 | 4.626 | 4.691 | 4.755 | 4.816 | 0.34 | 4.240 | 4.200 | 4.195 | 4.188 | 4.215 | 4.258 | 4.310 | 4.366 | 4.425 | 4.485 | 4.543 | 0.35 | 4.121 | 4.087 | 4.084 | 4.078 | 4.103 | 4.143 | 4.191 | 4.245 | 4.301 | 4.359 | 4.415 | 0.36 | 4.007 | 3.978 | 3.976 | 3.973 | 3.996 | 4.033 | 4.078 | 4.129 | 4.182 | 4.237 | 4.293 | 0.38 | 3.790 | 3.771 | 3.773 | 3.773 | 3.793 | 3.825 | 3.865 | 3.910 | 3.959 | 4.010 | 4.061 | 0.40 | 3.591 | 3.579 | 3.583 | 3.586 | 3.604 | 3.632 | 3.668 | 3.709 | 3.753 | 3.800 | 3.848 | | | | | | | | | | | | | 0.42 | 3.405 | 3.399 | 3.406 | 3.411 | 3.429 | 3.454 | 3.486 | 3.523 | 3.563 | 3.606 | 3.651 | 0.44 | 3.233 | 3.232 | 3.241 | 3.248 | 3.265 | 3.288 | 3.317 | 3.350 | 3.387 | 3.427 | 3.468 | 0.45 | 3.151 | 3.153 | 3.162 | 3.170 | 3.187 | 3.209 | 3.237 | 3.269 | 3.304 | 3.342 | 3.382 | 0.46 | 3.073 | 3.076 | 3.086 | 3.095 | 3.111 | 3.133 | 3.159 | 3.190 | 3.224 | 3.260 | 3.299 | 0.48 | 2.924 | 2.930 | 2.942 | 2.952 | 2.968 | 2.988 | 3.013 | 3.041 | 3.072 | 3.105 | 3.141 | 0.50 | 2.785 | 2.793 | 2.806 | 2.818 | 2.834 | 2.853 | 2.876 | 2.902 | 2.930 | 2.961 | 2.994 | | | | | | | | | | | | | 0.55 | 2.477 | 2.490 | 2.505 | 2.518 | 2.534 | 2.551 | 2.571 | 2.592 | 2.616 | 2.641 | 2.669 | 0.60 | 2.216 | 2.232 | 2.248 | 2.263 | 2.278 | 2.294 | 2.311 | 2.330 | 2.349 | 2.371 | 2.394 | 0.65 | 1.995 | 2.012 | 2.028 | 2.043 | 2.058 | 2.073 | 2.089 | 2.105 | 2.122 | 2.140 | 2.160 | 0.70 | 1.085 | 1.823 | 1.839 | 1.854 | 1.868 | 1.882 | 1.896 | 1.911 | 1.926 | 1.942 | 1.959 | 0.80 | 1.497 | 1.515 | 1.530 | 1.545 | 1.558 | 1.571 | 1.583 | 1.596 | 1.608 | 1.621 | 1.634 | 0.90 | 1.260 | 1.276 | 1.291 | 1.305 | 1.317 | 1.329 | 1.341 | 1.352 | 1.363 | 1.374 | 1.385 | 1.00 | 1.073 | 1.088 | 1.101 | 1.114 | 1.126 | 1.138 | 1.148 | 1.159 | 1.169 | 1.179 | 1.189 | | | | | | | | | | | | | 1.10 | 0.922 | 0.935 | 0.948 | 0.960 | 0.971 | 0.982 | 0.993 | 1.003 | 1.012 | 1.022 | 1.031 | 1.20 | 0.799 | 0.811 | 0.822 | 0.833 | 0.844 | 0.854 | 0.864 | 0.874 | 0.883 | 0.892 | 0.901 | 1.30 | 0.698 | 0.708 | 0.719 | 0.729 | 0.739 | 0.748 | 0.758 | 0.767 | 0.776 | 0.784 | 0.793 | 1.40 | 0.614 | 0.623 | 0.632 | 0.642 | 0.651 | 0.660 | 0.668 | 0.677 | 0.685 | 0.694 | 0.702 | 1.50 | 0.544 | 0.552 | 0.560 | 0.569 | 0.577 | 0.585 | 0.593 | 0.601 | 0.609 | 0.617 | 0.624 | | | | | | | | | | | | | 1.60 | 0.485 | 0.492 | 0.500 | 0.507 | 0.515 | 0.522 | 0.530 | 0.537 | 0.544 | 0.551 | 0.558 | 1.70 | 0.436 | 0.442 | 0.449 | 0.455 | 0.462 | 0.469 | 0.475 | 0.482 | 0.489 | 0.495 | 0.502 | 1.80 | 0.394 | 0.399 | 0.405 | 0.411 | 0.417 | 0.423 | 0.429 | 0.435 | 0.441 | 0.447 | 0.453 | 1.90 | 0.358 | 0.363 | 0.368 | 0.373 | 0.379 | 0.384 | 0.389 | 0.395 | 0.400 | 0.406 | 0.411 | 2.00 | 0.327 | 0.331 | 0.336 | 0.341 | 0.345 | 0.350 | 0.355 | 0.360 | 0.365 | 0.370 | 0.374 |
Element | Pt | Au | Hg | Tl | Pb | Bi | Po | At | Rn | Fr | Ra |
---|
Z | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 |
---|
Method | *RHF | RHF | RHF | *RHF | RHF | RHF | *RHF | *RHF | RHF | *RHF | *RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 10.813 | 10.573 | 10.964 | 12.109 | 12.597 | 13.096 | 13.368 | 13.473 | 13.492 | 18.715 | 20.561 | 0.01 | | 10.559 | 10.948 | | 12.573 | 13.070 | | | 13.470 | | | 0.02 | | 10.511 | 10.897 | | 12.494 | 12.989 | | | 13.403 | | | 0.03 | | 10.434 | 10.813 | | 12.366 | 12.857 | | | 13.292 | | | 0.04 | 10.55 | 10.328 | 10.698 | 11.71 | 12.193 | 12.678 | 12.95 | 13.09 | 13.139 | 17.14 | 18.94 | 0.05 | 10.40 | 10.195 | 10.555 | 11.51 | 11.979 | 12.456 | 12.74 | 12.89 | 12.949 | 16.41 | 18.15 | | | | | | | | | | | | | 0.06 | 10.23 | 10.040 | 10.387 | 11.27 | 11.730 | 12.197 | 12.49 | 12.65 | 12.724 | 15.64 | 17.31 | 0.07 | 10.03 | 9.865 | 10.197 | 11.00 | 11.454 | 11.908 | 12.21 | 12.38 | 12.469 | 14.87 | 16.42 | 0.08 | 9.82 | 9.673 | 9.989 | 10.72 | 11.155 | 11.595 | 11.90 | 12.08 | 12.187 | 14.13 | 15.54 | 0.09 | 9.60 | 9.467 | 9.766 | 10.42 | 10.840 | 11.264 | 11.57 | 11.76 | 11.884 | 13.42 | 14.69 | 0.10 | 9.37 | 9.251 | 9.533 | 10.12 | 10.516 | 10.921 | 11.22 | 11.43 | 11.565 | 12.77 | 13.88 | | | | | | | | | | | | | 0.11 | 9.13 | 9.028 | 9.291 | 9.81 | 10.186 | 10.571 | 10.87 | 11.08 | 11.232 | 12.16 | 13.12 | 0.12 | 8.882 | 8.799 | 9.045 | 9.500 | 9.855 | 10.219 | 10.509 | 10.729 | 10.892 | 11.605 | 12.419 | 0.13 | 8.636 | 8.568 | 8.796 | 9.195 | 9.527 | 9.869 | 10.153 | 10.375 | 10.546 | 11.093 | 11.776 | 0.14 | 8.389 | 8.337 | 8.547 | 8.896 | 9.203 | 9.523 | 9.798 | 10.021 | 10.199 | 10.620 | 11.187 | 0.15 | 8.145 | 8.106 | 8.299 | 8.603 | 8.888 | 9.186 | 9.449 | 9.671 | 9.854 | 10.180 | 10.648 | | | | | | | | | | | | | 0.16 | 7.904 | 7.877 | 8.055 | 8.320 | 8.581 | 8.857 | 9.109 | 9.328 | 9.512 | 9.770 | 10.155 | 0.17 | 7.667 | 7.652 | 7.815 | 8.046 | 8.285 | 8.539 | 8.779 | 8.991 | 9.177 | 9.386 | 9.702 | 0.18 | 7.436 | 7.431 | 7.579 | 7.781 | 7.999 | 8.233 | 8.459 | 8.666 | 8.849 | 9.023 | 9.285 | 0.19 | 7.210 | 7.214 | 7.350 | 7.526 | 7.724 | 7.939 | 8.151 | 8.350 | 8.531 | 8.681 | 8.899 | 0.20 | 6.991 | 7.003 | 7.128 | 7.282 | 7.461 | 7.658 | 7.856 | 8.046 | 8.223 | 8.356 | 8.540 | | | | | | | | | | | | | 0.22 | 6.572 | 6.598 | 6.702 | 6.822 | 6.969 | 7.132 | 7.303 | 3.474 | 7.639 | 7.754 | 7.891 | 0.24 | 6.181 | 6.216 | 6.305 | 6.399 | 6.520 | 6.654 | 6.800 | 6.952 | 7.102 | 7.208 | 7.318 | 0.25 | 5.995 | 6.035 | 6.116 | 6.201 | 6.310 | 6.432 | 6.567 | 6.709 | 6.852 | 6.954 | 7.055 | 0.26 | 5.817 | 5.859 | 5.934 | 6.011 | 6.110 | 6.221 | 6.345 | 6.477 | 6.612 | 6.712 | 6.807 | 0.28 | 5.478 | 5.525 | 5.591 | 5.654 | 5.736 | 5.828 | 5.933 | 6.047 | 6.166 | 6.261 | 6.347 | 0.30 | 5.164 | 5.214 | 5.272 | 5.327 | 5.395 | 5.472 | 5.560 | 5.658 | 5.762 | 5.852 | 5.931 | | | | | | | | | | | | | 0.32 | 4.873 | 4.924 | 4.976 | 5.025 | 5.083 | 5.148 | 5.222 | 5.305 | 5.397 | 5.480 | 5.555 | 0.34 | 4.603 | 4.654 | 4.702 | 4.746 | 4.797 | 4.852 | 4.915 | 4.987 | 5.065 | 5.141 | 5.212 | 0.35 | 4.475 | 4.526 | 4.572 | 4.614 | 4.662 | 4.714 | 4.772 | 4.838 | 4.912 | 4.984 | 5.053 | 0.36 | 4.352 | 4.403 | 4.447 | 4.488 | 4.533 | 4.581 | 4.636 | 4.697 | 4.765 | 4.834 | 4.900 | 0.38 | 4.120 | 4.169 | 4.211 | 4.249 | 4.290 | 4.333 | 4.380 | 4.433 | 4.492 | 4.555 | 4.616 | 0.40 | 3.905 | 3.952 | 3.991 | 4.028 | 4.066 | 4.104 | 4.146 | 4.192 | 4.244 | 4.300 | 4.356 | | | | | | | | | | | | | 0.42 | 3.704 | 3.750 | 3.787 | 3.823 | 3.858 | 3.893 | 3.931 | 3.972 | 4.017 | 4.067 | 4.118 | 0.44 | 3.518 | 3.562 | 3.597 | 3.632 | 3.665 | 3.698 | 3.732 | 3.769 | 3.808 | 3.854 | 3.901 | 0.45 | 3.430 | 3.472 | 3.507 | 3.541 | 3.573 | 3.606 | 3.639 | 3.673 | 3.711 | 3.754 | 3.798 | 0.46 | 3.345 | 3.386 | 3.420 | 3.454 | 3.485 | 3.517 | 3.548 | 3.582 | 3.617 | 3.658 | 3.700 | 0.48 | 3.184 | 3.223 | 3.256 | 3.288 | 3.318 | 3.348 | 3.378 | 3.408 | 3.441 | 3.477 | 3.516 | 0.50 | 3.034 | 3.070 | 3.102 | 3.133 | 3.162 | 3.191 | 3.219 | 3.248 | 3.277 | 3.311 | 3.346 | | | | | | | | | | | | | 0.55 | 2.701 | 2.732 | 2.760 | 2.789 | 2.816 | 2.842 | 2.868 | 2.893 | 2.918 | 2.945 | 2.974 | 0.60 | 2.420 | 2.446 | 2.471 | 2.497 | 2.522 | 2.546 | 2.570 | 2.593 | 2.616 | 2.639 | 2.663 | 0.65 | 2.181 | 2.203 | 2.225 | 2.248 | 2.271 | 2.293 | 2.315 | 2.337 | 2.358 | 2.378 | 2.399 | 0.70 | 1.976 | 1.995 | 2.015 | 2.035 | 2.055 | 2.076 | 2.096 | 2.116 | 2.135 | 2.154 | 2.173 | 0.80 | 1.647 | 1.661 | 1.676 | 1.692 | 1.708 | 1.725 | 1.742 | 1.758 | 1.775 | 1.791 | 1.808 | 0.90 | 1.396 | 1.407 | 1.419 | 1.431 | 1.444 | 1.457 | 1.471 | 1.485 | 1.499 | 1.513 | 1.527 | 1.00 | 1.198 | 1.208 | 1.218 | 1.228 | 1.239 | 1.249 | 1.260 | 1.272 | 1.283 | 1.295 | 1.307 | | | | | | | | | | | | | 1.10 | 1.040 | 1.048 | 1.057 | 1.066 | 1.075 | 1.084 | 1.093 | 1.102 | 1.112 | 1.122 | 1.132 | 1.20 | 0.909 | 0.918 | 0.926 | 0.934 | 0.942 | 0.949 | 0.957 | 0.965 | 0.974 | 0.982 | 0.990 | 1.30 | 0.801 | 0.809 | 0.816 | 0.824 | 0.831 | 0.838 | 0.846 | 0.853 | 0.860 | 0.867 | 0.874 | 1.40 | 0.709 | 0.717 | 0.724 | 0.731 | 0.738 | 0.745 | 0.752 | 0.758 | 0.765 | 0.771 | 0.778 | 1.50 | 0.632 | 0.639 | 0.646 | 0.653 | 0.659 | 0.666 | 0.672 | 0.678 | 0.684 | 0.690 | 0.696 | | | | | | | | | | | | | 1.60 | 0.565 | 0.572 | 0.579 | 0.585 | 0.591 | 0.598 | 0.603 | 0.609 | 0.615 | 0.621 | 0.626 | 1.70 | 0.508 | 0.514 | 0.521 | 0.527 | 0.533 | 0.538 | 0.544 | 0.550 | 0.555 | 0.561 | 0.566 | 1.80 | 0.459 | 0.465 | 0.471 | 0.476 | 0.482 | 0.488 | 0.493 | 0.498 | 0.503 | 0.508 | 0.513 | 1.90 | 0.416 | 0.422 | 0.427 | 0.432 | 0.438 | 0.443 | 0.448 | 0.453 | 0.458 | 0.463 | 0.468 | 2.00 | 0.379 | 0.384 | 0.389 | 0.394 | 0.399 | 0.404 | 0.409 | 0.413 | 0.418 | 0.423 | 0.427 |
Element | Ac | Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf |
---|
Z | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 |
---|
Method | *RHF | *RHF | *RHF | RHF | *RHF | *RHF | *RHF | *RHF | *RHF | *RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | |
---|
0.00 | 20.484 | 20.115 | 19.568 | 19.119 | 18.759 | 18.191 | 17.840 | 17.710 | 17.406 | 16.841 | 0.01 | | | | 19.047 | | | | | | | 0.02 | | | | 18.825 | | | | | | | 0.03 | | | | 18.470 | | | | | | | 0.04 | 19.10 | 18.92 | 18.37 | 17.999 | 17.70 | 17.10 | 16.80 | 16.80 | 16.53 | 16.28 | 0.05 | 18.41 | 18.33 | 17.77 | 17.436 | 17.16 | 16.55 | 16.28 | 16.33 | 16.08 | 15.85 | | | | | | | | | | | | 0.06 | 17.64 | 17.66 | 17.11 | 16.805 | 16.55 | 15.95 | 15.70 | 15.80 | 15.58 | 15.37 | 0.07 | 16.84 | 16.93 | 16.39 | 16.131 | 15.91 | 15.31 | 15.09 | 15.24 | 15.04 | 14.84 | 0.08 | 16.01 | 16.19 | 15.66 | 15.436 | 15.25 | 14.65 | 14.47 | 14.66 | 14.48 | 14.30 | 0.09 | 15.19 | 15.43 | 14.92 | 14.738 | 14.58 | 14.00 | 13.84 | 14.06 | 13.91 | 13.75 | 0.10 | 14.40 | 14.68 | 14.20 | 14.052 | 13.92 | 13.37 | 13.24 | 13.47 | 13.33 | 13.20 | | | | | | | | | | | | 0.11 | 13.64 | 13.95 | 13.51 | 13.389 | 13.28 | 12.76 | 12.65 | 12.90 | 12.78 | 12.66 | 0.12 | 12.923 | 13.255 | 12.850 | 12.756 | 12.665 | 12.191 | 12.095 | 12.344 | 12.241 | 12.135 | 0.13 | 12.253 | 12.594 | 12.228 | 12.157 | 12.085 | 11.653 | 11.572 | 11.817 | 11.729 | 11.637 | 0.14 | 11.632 | 11.972 | 11.646 | 11.595 | 11.540 | 11.149 | 11.083 | 11.319 | 11.243 | 11.164 | 0.15 | 11.058 | 11.388 | 11.102 | 11.069 | 11.029 | 10.679 | 10.626 | 10.848 | 10.784 | 10.716 | | | | | | | | | | | | 0.16 | 10.528 | 10.845 | 10.597 | 10.579 | 10.551 | 10.243 | 10.200 | 10.407 | 10.353 | 10.294 | 0.17 | 10.038 | 10.339 | 10.128 | 10.122 | 10.104 | 9.836 | 9.803 | 9.993 | 9.948 | 9.898 | 0.18 | 9.586 | 9.868 | 9.691 | 9.696 | 9.688 | 9.457 | 9.433 | 9.605 | 9.568 | 9.527 | 0.19 | 9.168 | 9.430 | 9.285 | 9.299 | 9.300 | 9.102 | 9.086 | 9.241 | 9.212 | 9.178 | 0.20 | 8.780 | 9.022 | 8.906 | 8.928 | 8.936 | 8.770 | 8.760 | 8.900 | 8.878 | 8.850 | | | | | | | | | | | | 0.22 | 8.083 | 8.287 | 8.221 | 8.254 | 8.275 | 8.163 | 8.164 | 8.277 | 8.266 | 8.249 | 0.24 | 7.474 | 7.645 | 7.617 | 7.659 | 7.689 | 7.619 | 7.631 | 7.721 | 7.720 | 7.713 | 0.25 | 7.196 | 7.353 | 7.341 | 7.387 | 7.420 | 7.368 | 7.384 | 7.465 | 7.468 | 7.466 | 0.26 | 6.935 | 7.079 | 7.081 | 7.129 | 7.165 | 7.129 | 7.148 | 7.222 | 7.229 | 7.231 | 0.28 | 6.455 | 6.578 | 6.600 | 6.652 | 6.694 | 6.683 | 6.708 | 6.770 | 6.784 | 6.793 | 0.30 | 6.025 | 6.129 | 6.167 | 6.221 | 6.266 | 6.274 | 6.304 | 6.358 | 6.378 | 6.393 | | | | | | | | | | | | 0.32 | 5.637 | 5.727 | 5.775 | 5.830 | 5.878 | 5.899 | 5.933 | 5.981 | 6.006 | 6.026 | 0.34 | 5.285 | 5.364 | 5.418 | 5.473 | 5.523 | 5.553 | 5.591 | 5.635 | 5.664 | 5.687 | 0.35 | 5.122 | 5.196 | 5.252 | 5.307 | 5.357 | 5.391 | 5.429 | 5.472 | 5.502 | 5.528 | 0.36 | 4.966 | 5.036 | 5.093 | 5.148 | 5.197 | 5.235 | 5.274 | 5.316 | 5.347 | 5.374 | 0.38 | 4.675 | 4.738 | 4.796 | 4.850 | 4.899 | 4.940 | 4.981 | 5.021 | 5.055 | 5.084 | 0.40 | 4.410 | 4.466 | 4.524 | 4.576 | 4.625 | 4.669 | 4.710 | 4.749 | 4.784 | 4.815 | | | | | | | | | | | | 0.42 | 4.168 | 4.218 | 4.275 | 4.325 | 4.372 | 4.417 | 4.459 | 4.497 | 4.532 | 4.565 | 0.44 | 3.946 | 3.992 | 4.046 | 4.094 | 4.140 | 4.185 | 4.226 | 4.263 | 4.299 | 4.333 | 0.45 | 3.842 | 3.885 | 3.938 | 3.985 | 4.030 | 4.076 | 4.116 | 4.152 | 4.189 | 4.222 | 0.46 | 3.742 | 3.784 | 3.835 | 3.881 | 3.925 | 3.970 | 4.010 | 4.046 | 4.082 | 4.116 | 0.48 | 3.554 | 3.592 | 3.641 | 3.685 | 3.727 | 3.771 | 3.810 | 3.844 | 3.880 | 3.914 | 0.50 | 3.381 | 3.416 | 3.462 | 3.503 | 3.543 | 3.586 | 3.624 | 3.657 | 3.693 | 3.726 | | | | | | | | | | | | 0.55 | 3.003 | 3.032 | 3.071 | 3.106 | 3.141 | 3.179 | 3.213 | 3.244 | 3.277 | 3.309 | 0.60 | 2.687 | 2.712 | 2.744 | 2.775 | 2.805 | 2.839 | 2.869 | 2.897 | 2.927 | 2.957 | 0.65 | 2.421 | 2.442 | 2.470 | 2.495 | 2.522 | 2.551 | 2.578 | 2.603 | 2.630 | 2.657 | 0.70 | 2.193 | 2.212 | 2.235 | 2.257 | 2.280 | 2.306 | 2.330 | 2.352 | 2.376 | 2.400 | 0.80 | 1.824 | 1.840 | 1.857 | 1.875 | 1.893 | 1.912 | 1.930 | 1.949 | 1.968 | 1.987 | 0.90 | 1.541 | 1.554 | 1.568 | 1.582 | 1.597 | 1.611 | 1.626 | 1.641 | 1.657 | 1.673 | 1.00 | 1.318 | 1.330 | 1.342 | 1.353 | 1.365 | 1.377 | 1.389 | 1.402 | 1.415 | 1.427 | | | | | | | | | | | | 1.10 | 1.142 | 1.152 | 1.161 | 1.171 | 1.181 | 1.191 | 1.201 | 1.212 | 1.222 | 1.233 | 1.20 | 0.999 | 1.007 | 1.016 | 1.024 | 1.033 | 1.041 | 1.049 | 1.058 | 1.067 | 1.076 | 1.30 | 0.882 | 0.889 | 0.896 | 0.904 | 0.911 | 0.918 | 0.926 | 0.933 | 0.941 | 0.948 | 1.40 | 0.784 | 0.791 | 0.797 | 0.803 | 0.810 | 0.816 | 0.823 | 0.830 | 0.836 | 0.843 | 1.50 | 0.702 | 0.708 | 0.714 | 0.720 | 0.725 | 0.731 | 0.737 | 0.743 | 0.748 | 0.754 | | | | | | | | | | | | 1.60 | 0.632 | 0.637 | 0.643 | 0.649 | 0.653 | 0.659 | 0.664 | 0.669 | 0.674 | 0.679 | 1.70 | 0.571 | 0.576 | 0.581 | 0.585 | 0.591 | 0.596 | 0.601 | 0.606 | 0.611 | 0.165 | 1.80 | 0.518 | 0.523 | 0.528 | 0.534 | 0.537 | 0.542 | 0.547 | 0.551 | 0.555 | 0.560 | 1.90 | 0.472 | 0.477 | 0.481 | 0.485 | 0.490 | 0.495 | 0.499 | 0.503 | 0.507 | 0.511 | 2.00 | 0.432 | 0.436 | 0.440 | 0.443 | 0.449 | 0.453 | 0.457 | 0.461 | 0.465 | 0.469 |
|
Element | H1− | Li1+ | Be2+ | O1− | F1− | Na1+ | Mg2+ | Al3+ | Si4+ | Cl1− | K1+ |
---|
Z | 1 | 3 | 4 | 8 | 9 | 11 | 12 | 13 | 14 | 17 | 19 |
---|
Method | HF | RHF | RHF | HF | HF | RHF | RHF | HF | HF | RHF | RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | | 0.157 | 0.082 | | | 1.130 | 0.831 | | | 6.770 | 3.436 | 0.01 | | 239.497 | 478.762 | | | 240.469 | 479.511 | | | −232.585 | 242.773 | 0.02 | | 59.992 | 119.752 | | | 60.963 | 120.500 | | | −53.125 | 63.260 | 0.03 | | 26.750 | 53.268 | | | 27.719 | 54.015 | | | −19.957 | 30.004 | 0.04 | −12.00 | 15.115 | 29.999 | −11.74 | −12.21 | 16.081 | 30.745 | 45.52 | 60.34 | −8.423 | 18.349 | 0.05 | −6.78 | 9.730 | 19.229 | −6.41 | −6.85 | 10.692 | 19.972 | 29.36 | 38.80 | −3.162 | 12.939 | | | | | | | | | | | | | 0.06 | −4.03 | 6.804 | 13.378 | −3.55 | −3.97 | 7.762 | 14.119 | 20.58 | 27.10 | −0.381 | 9.983 | 0.07 | −2.45 | 5.040 | 9.850 | −1.86 | −2.25 | 5.993 | 10.589 | 15.29 | 20.05 | 1.219 | 8.184 | 0.08 | −1.48 | 3.894 | 7.560 | −0.79 | −1.16 | 4.841 | 8.296 | 11.85 | 15.46 | 2.187 | 6.999 | 0.09 | −0.87 | 3.109 | 5.990 | −0.09 | −0.43 | 4.049 | 6.722 | 9.49 | 12.32 | 2.783 | 6.169 | 0.10 | −0.47 | 2.546 | 4.867 | 0.39 | 0.08 | 3.480 | 5.595 | 7.81 | 10.08 | 3.147 | 5.559 | | | | | | | | | | | | | 0.11 | −0.20 | 2.130 | 4.036 | 0.72 | 0.43 | 3.056 | 4.760 | 6.56 | 8.41 | 3.361 | 5.092 | 0.12 | −0.023 | 1.813 | 3.404 | 0.949 | 0.688 | 2.731 | 4.123 | 5.610 | 7.147 | 3.472 | 4.720 | 0.13 | 0.095 | 1.567 | 2.912 | 1.107 | 0.870 | 2.475 | 3.626 | 4.868 | 6.162 | 3.513 | 4.416 | 0.14 | 0.173 | 1.370 | 2.522 | 1.215 | 1.000 | 2.269 | 3.230 | 4.280 | 5.379 | 3.504 | 4.160 | 0.15 | 0.224 | 1.212 | 2.207 | 1.285 | 1.092 | 2.100 | 2.909 | 3.804 | 4.747 | 3.461 | 3.939 | | | | | | | | | | | | | 0.16 | 0.257 | 1.082 | 1.949 | 1.329 | 1.157 | 1.960 | 2.645 | 3.413 | 4.230 | 3.393 | 3.745 | 0.17 | 0.276 | 0.974 | 1.735 | 1.352 | 1.200 | 1.841 | 2.425 | 3.089 | 3.800 | 3.308 | 3.571 | 0.18 | 0.286 | 0.883 | 1.556 | 1.359 | 1.226 | 1.738 | 2.239 | 2.817 | 3.440 | 3.211 | 3.414 | 0.19 | 0.288 | 0.806 | 1.404 | 1.355 | 1.239 | 1.650 | 2.081 | 2.585 | 3.135 | 3.108 | 3.269 | 0.20 | 0.287 | 0.740 | 1.274 | 1.343 | 1.242 | 1.571 | 1.944 | 2.387 | 2.873 | 3.000 | 3.135 | | | | | | | | | | | | | 0.22 | 0.276 | 0.634 | 1.066 | 1.300 | 1.228 | 1.440 | 1.720 | 2.066 | 2.451 | 2.779 | 2.893 | 0.24 | 0.259 | 0.552 | 0.907 | 1.243 | 1.194 | 1.332 | 1.546 | 1.819 | 2.129 | 2.563 | 2.676 | 0.25 | 0.250 | 0.518 | 0.841 | 1.212 | 1.173 | 1.284 | 1.472 | 1.716 | 1.995 | 2.458 | 2.575 | 0.26 | 0.240 | 0.487 | 0.783 | 1.179 | 1.150 | 1.240 | 1.406 | 1.624 | 1.876 | 2.357 | 2.479 | 0.28 | 0.221 | 0.435 | 0.685 | 1.112 | 1.099 | 1.161 | 1.290 | 1.466 | 1.674 | 2.165 | 2.300 | 0.30 | 0.203 | 0.393 | 0.605 | 1.046 | 1.046 | 1.092 | 1.193 | 1.336 | 1.509 | 1.988 | 2.135 | | | | | | | | | | | | | 0.32 | 0.186 | 0.357 | 0.539 | 0.981 | 0.992 | 1.029 | 1.110 | 1.228 | 1.372 | 1.827 | 1.983 | 0.34 | 0.170 | 0.327 | 0.485 | 0.918 | 0.939 | 0.972 | 1.038 | 1.136 | 1.257 | 1.680 | 1.843 | 0.35 | 0.163 | 0.314 | 0.461 | 0.889 | 0.912 | 0.946 | 1.005 | 1.094 | 1.206 | 1.613 | 1.778 | 0.36 | 0.156 | 0.301 | 0.439 | 0.860 | 0.887 | 0.920 | 0.974 | 1.056 | 1.159 | 1.548 | 1.715 | 0.38 | 0.143 | 0.279 | 0.400 | 0.804 | 0.837 | 0.872 | 0.917 | 0.987 | 1.075 | 1.429 | 1.596 | 0.40 | 0.132 | 0.259 | 0.366 | 0.753 | 0.789 | 0.827 | 0.866 | 0.925 | 1.001 | 1.322 | 1.488 | | | | | | | | | | | | | 0.42 | 0.122 | 0.242 | 0.337 | 0.704 | 0.744 | 0.785 | 0.820 | 0.871 | 0.937 | 1.226 | 1.388 | 0.44 | 0.112 | 0.227 | 0.312 | 0.660 | 0.702 | 0.746 | 0.777 | 0.822 | 0.880 | 1.139 | 1.296 | 0.45 | 0.108 | 0.220 | 0.300 | 0.639 | 0.682 | 0.727 | 0.757 | 0.799 | 0.853 | 1.099 | 1.253 | 0.46 | 0.104 | 0.213 | 0.290 | 0.618 | 0.662 | 0.709 | 0.738 | 0.778 | 0.829 | 1.061 | 1.212 | 0.48 | 0.096 | 0.200 | 0.270 | 0.580 | 0.625 | 0.675 | 0.701 | 0.737 | 0.783 | 0.991 | 1.135 | 0.50 | 0.090 | 0.189 | 0.252 | 0.544 | 0.590 | 0.642 | 0.668 | 0.701 | 0.741 | 0.928 | 1.064 | | | | | | | | | | | | | 0.55 | 0.075 | 0.165 | 0.216 | 0.467 | 0.512 | 0.569 | 0.593 | 0.620 | 0.652 | 0.796 | 0.912 | 0.60 | 0.064 | 0.145 | 0.188 | 0.403 | 0.446 | 0.506 | 0.529 | 0.553 | 0.580 | 0.691 | 0.789 | 0.65 | 0.055 | 0.129 | 0.165 | 0.351 | 0.391 | 0.451 | 0.474 | 0.496 | 0.519 | 0.608 | 0.690 | 0.70 | 0.048 | 0.115 | 0.146 | 0.307 | 0.345 | 0.403 | 0.426 | 0.447 | 0.468 | 0.541 | 0.609 | 0.80 | 0.037 | 0.093 | 0.118 | 0.241 | 0.272 | 0.325 | 0.347 | 0.367 | 0.385 | 0.439 | 0.488 | 0.90 | 0.029 | 0.077 | 0.097 | 0.193 | 0.219 | 0.266 | 0.286 | 0.305 | 0.321 | 0.366 | 0.402 | 1.00 | 0.024 | 0.064 | 0.081 | 0.159 | 0.180 | 0.221 | 0.239 | 0.256 | 0.271 | 0.311 | 0.338 | | | | | | | | | | | | | 1.10 | 0.020 | 0.054 | 0.069 | 0.133 | 0.150 | 0.185 | 0.201 | 0.217 | 0.231 | 0.267 | 0.290 | 1.20 | 0.017 | 0.046 | 0.059 | 0.113 | 0.128 | 0.157 | 0.172 | 0.186 | 0.198 | 0.232 | 0.252 | 1.30 | 0.014 | 0.040 | 0.052 | 0.097 | 0.110 | 0.135 | 0.148 | 0.160 | 0.172 | 0.202 | 0.221 | 1.40 | 0.012 | 0.035 | 0.045 | 0.085 | 0.095 | 0.118 | 0.129 | 0.140 | 0.150 | 0.178 | 0.195 | 1.50 | 0.011 | 0.031 | 0.040 | 0.075 | 0.084 | 0.103 | 0.113 | 0.123 | 0.132 | 0.158 | 0.173 | | | | | | | | | | | | | 1.60 | | 0.027 | 0.035 | | | 0.091 | 0.100 | | | 0.141 | 0.155 | 1.70 | | 0.024 | 0.032 | | | 0.081 | 0.089 | | | 0.126 | 0.139 | 1.80 | | 0.022 | 0.028 | | | 0.073 | 0.080 | | | 0.113 | 0.125 | 1.90 | | 0.020 | 0.026 | | | 0.066 | 0.072 | | | 0.102 | 0.114 | 2.00 | | 0.018 | 0.023 | | | 0.060 | 0.065 | | | 0.093 | 0.103 |
Element | Ca2+ | Sc3+ | Ti2+ | Ti3+ | Ti4+ | V2+ | V3+ | V5+ | Cr2+ | Cr3+ | Mn2+ |
---|
Z | 20 | 21 | 22 | 22 | 22 | 23 | 23 | 23 | 24 | 24 | 25 |
---|
Method | RHF | HF | HF | HF | HF | RHF | HF | HF | HF | HF | RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 2.711 | | | | | 2.904 | | | | | 2.846 | 0.01 | 481.390 | | | | | 481.582 | | | | | 481.525 | 0.02 | 122.375 | | | | | 122.566 | | | | | 122.510 | 0.03 | 55.883 | | | | | 56.074 | | | | | 56.018 | 0.04 | 32.602 | 47.08 | 32.80 | 47.15 | 61.67 | 32.791 | 47.18 | 76.36 | 32.79 | 47.19 | 32.738 | 0.05 | 21.817 | 30.91 | 22.01 | 30.98 | 40.13 | 22.005 | 31.02 | 49.43 | 22.00 | 31.03 | 21.953 | | | | | | | | | | | | | 0.06 | 15.948 | 22.13 | 16.14 | 22.19 | 28.42 | 16.134 | 22.23 | 34.80 | 16.13 | 22.24 | 16.085 | 0.07 | 12.399 | 16.82 | 12.59 | 16.89 | 21.35 | 12.583 | 16.92 | 25.98 | 12.58 | 16.93 | 12.537 | 0.08 | 10.085 | 13.37 | 10.27 | 13.44 | 16.77 | 10.267 | 13.47 | 20.24 | 10.26 | 13.48 | 10.225 | 0.09 | 8.489 | 11.00 | 8.67 | 11.07 | 13.62 | 8.668 | 11.10 | 16.31 | 8.67 | 11.11 | 8.630 | 0.10 | 7.336 | 9.30 | 7.52 | 9.36 | 11.36 | 7.514 | 9.39 | 13.49 | 7.51 | 9.41 | 7.479 | | | | | | | | | | | | | 0.11 | 6.473 | 8.03 | 6.65 | 8.09 | 9.68 | 6.648 | 8.13 | 11.41 | 6.65 | 8.14 | 6.618 | 0.12 | 5.807 | 7.057 | 5.977 | 7.120 | 8.400 | 5.980 | 7.155 | 9.815 | 5.983 | 7.172 | 5.954 | 0.13 | 5.279 | 6.295 | 5.444 | 6.359 | 7.400 | 5.449 | 6.394 | 8.574 | 5.455 | 6.410 | 5.428 | 0.14 | 4.850 | 5.684 | 5.011 | 5.747 | 6.603 | 5.018 | 5.782 | 7.584 | 5.026 | 5.800 | 5.002 | 0.15 | 4.495 | 5.185 | 4.653 | 5.247 | 5.954 | 4.661 | 5.284 | 6.784 | 4.671 | 5.302 | 4.650 | | | | | | | | | | | | | 0.16 | 4.196 | 4.770 | 4.349 | 4.832 | 5.418 | 4.360 | 4.868 | 6.126 | 4.372 | 4.888 | 4.353 | 0.17 | 3.939 | 4.421 | 4.089 | 4.481 | 4.971 | 4.102 | 4.518 | 5.577 | 4.116 | 4.539 | 4.100 | 0.18 | 3.716 | 4.121 | 3.863 | 4.182 | 4.591 | 3.877 | 4.220 | 5.113 | 3.894 | 4.242 | 3.880 | 0.19 | 3.519 | 3.863 | 3.663 | 3.923 | 4.266 | 3.679 | 3.961 | 4.719 | 3.698 | 3.984 | 3.686 | 0.20 | 3.343 | 3.637 | 3.485 | 3.697 | 3.984 | 3.503 | 3.735 | 4.378 | 3.523 | 3.759 | 3.514 | | | | | | | | | | | | | 0.22 | 3.041 | 3.259 | 3.178 | 3.318 | 3.520 | 3.200 | 3.358 | 3.824 | 3.224 | 3.384 | 3.220 | 0.24 | 2.787 | 2.953 | 2.920 | 3.012 | 3.155 | 2.946 | 3.053 | 3.391 | 2.973 | 3.081 | 2.975 | 0.25 | 2.674 | 2.821 | 2.806 | 2.879 | 2.998 | 2.833 | 2.921 | 3.209 | 2.862 | 2.950 | 2.865 | 0.26 | 2.568 | 2.699 | 2.699 | 2.757 | 2.857 | 2.727 | 2.799 | 3.045 | 2.758 | 2.830 | 2.764 | 0.28 | 2.376 | 2.482 | 2.504 | 2.540 | 2.610 | 2.536 | 2.584 | 2.761 | 2.569 | 2.616 | 2.579 | 0.30 | 2.204 | 2.294 | 2.331 | 2.352 | 2.399 | 2.365 | 2.396 | 2.524 | 2.401 | 2.430 | 2.415 | | | | | | | | | | | | | 0.32 | 2.049 | 2.128 | 2.174 | 2.185 | 2.217 | 2.211 | 2.231 | 2.322 | 2.249 | 2.266 | 2.266 | 0.34 | 1.907 | 1.980 | 2.032 | 2.037 | 2.057 | 2.071 | 2.073 | 2.147 | 2.111 | 2.120 | 2.131 | 0.35 | 1.842 | 1.911 | 1.966 | 1.968 | 1.984 | 2.005 | 2.015 | 2.068 | 2.046 | 2.053 | 2.068 | 0.36 | 1.778 | 1.846 | 1.903 | 1.903 | 1.915 | 1.943 | 1.950 | 1.994 | 1.984 | 1.988 | 2.007 | 0.38 | 1.660 | 1.725 | 1.783 | 1.781 | 1.788 | 1.825 | 1.829 | 1.858 | 1.867 | 1.868 | 1.893 | 0.40 | 1.551 | 1.614 | 1.673 | 1.670 | 1.673 | 1.716 | 1.718 | 1.736 | 1.759 | 1.758 | 1.787 | | | | | | | | | | | | | 0.42 | 1.451 | 1.512 | 1.572 | 1.568 | 1.569 | 1.615 | 1.616 | 1.627 | 1.659 | 1.657 | 1.688 | 0.44 | 1.359 | 1.419 | 1.478 | 1.474 | 1.473 | 1.522 | 1.522 | 1.528 | 1.566 | 1.563 | 1.597 | 0.45 | 1.316 | 1.375 | 1.433 | 1.429 | 1.428 | 1.477 | 1.477 | 1.481 | 1.522 | 1.519 | 1.553 | 0.46 | 1.274 | 1.333 | 1.391 | 1.387 | 1.385 | 1.435 | 1.434 | 1.437 | 1.480 | 1.476 | 1.511 | 0.48 | 1.196 | 1.253 | 1.310 | 1.306 | 1.304 | 1.354 | 1.354 | 1.354 | 1.399 | 1.395 | 1.432 | 0.50 | 1.124 | 1.180 | 1.235 | 1.232 | 1.229 | 1.279 | 1.279 | 1.277 | 1.324 | 1.320 | 1.357 | | | | | | | | | | | | | 0.55 | 0.967 | 1.019 | 1.070 | 1.068 | 1.066 | 1.113 | 1.113 | 1.110 | 1.156 | 1.154 | 1.190 | 0.60 | 0.838 | 0.886 | 0.933 | 0.931 | 0.930 | 0.973 | 0.974 | 0.971 | 1.015 | 1.013 | 1.049 | 0.65 | 0.733 | 0.776 | 0.818 | 0.817 | 0.816 | 0.856 | 0.857 | 0.855 | 0.895 | 0.894 | 0.928 | 0.70 | 0.647 | 0.685 | 0.722 | 0.722 | 0.721 | 0.757 | 0.758 | 0.756 | 0.793 | 0.792 | 0.824 | 0.80 | 0.515 | 0.544 | 0.574 | 0.574 | 0.574 | 0.602 | 0.603 | 0.603 | 0.632 | 0.632 | 0.659 | 0.90 | 0.422 | 0.444 | 0.467 | 0.467 | 0.467 | 0.490 | 0.491 | 0.491 | 0.515 | 0.515 | 0.538 | 1.00 | 0.354 | 0.371 | 0.389 | 0.389 | 0.389 | 0.408 | 0.408 | 0.408 | 0.427 | 0.427 | 0.446 | | | | | | | | | | | | | 1.10 | 0.302 | 0.316 | 0.331 | 0.331 | 0.330 | 0.345 | 0.346 | 0.345 | 0.361 | 0.361 | 0.377 | 1.20 | 0.262 | 0.273 | 0.285 | 0.285 | 0.285 | 0.297 | 0.297 | 0.297 | 0.310 | 0.310 | 0.323 | 1.30 | 0.230 | 0.239 | 0.249 | 0.249 | 0.249 | 0.259 | 0.259 | 0.259 | 0.270 | 0.270 | 0.280 | 1.40 | 0.203 | 0.211 | 0.220 | 0.220 | 0.219 | 0.228 | 0.228 | 0.228 | 0.237 | 0.237 | 0.246 | 1.50 | 0.180 | 0.188 | 0.195 | 0.195 | 0.195 | 0.203 | 0.203 | 0.202 | 0.211 | 0.211 | 0.218 | | | | | | | | | | | | | 1.60 | 0.161 | | | | | 0.181 | | | | | 0.195 | 1.70 | 0.145 | | | | | 0.163 | | | | | 0.175 | 1.80 | 0.131 | | | | | 0.148 | | | | | 0.159 | 1.90 | 0.119 | | | | | 0.134 | | | | | 0.144 | 2.00 | 0.108 | | | | | 0.123 | | | | | 0.132 |
Element | Mn3+ | Mn4+ | Fe2+ | Fe3+ | Co2+ | Co3+ | Ni2+ | Ni3+ | Cu1+ | Cu2+ | Zn2+ |
---|
Z | 25 | 25 | 26 | 26 | 27 | 27 | 28 | 28 | 29 | 29 | 30 |
---|
Method | HF | HF | RHF | RHF | RHF | HF | RHF | HF | RHF | HF | RHF |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | | | 2.802 | 2.298 | 2.754 | | 2.703 | | 3.280 | | 2.599 | 0.01 | | | 481.481 | 720.318 | 481.433 | | 481.382 | | 242.618 | | 481.278 | 0.02 | | | 122.467 | 181.800 | 122.419 | | 122.368 | | 63.107 | | 122.265 | 0.03 | | | 55.976 | 82.070 | 55.928 | | 55.878 | | 29.855 | | 55.776 | 0.04 | 47.18 | 61.76 | 32.696 | 47.160 | 32.650 | 47.15 | 32.600 | 47.12 | 18.206 | 32.55 | 32.499 | 0.05 | 31.02 | 40.22 | 21.913 | 30.996 | 21.867 | 30.98 | 21.819 | 30.96 | 12.803 | 21.77 | 21.719 | | | | | | | | | | | | | 0.06 | 22.23 | 28.51 | 16.046 | 22.210 | 16.002 | 22.20 | 15.955 | 22.17 | 9.856 | 15.90 | 15.857 | 0.07 | 16.93 | 21.44 | 12.500 | 16.907 | 12.457 | 16.90 | 12.411 | 16.87 | 8.066 | 12.36 | 12.316 | 0.08 | 13.48 | 16.85 | 10.189 | 13.459 | 10.148 | 13.45 | 10.103 | 13.43 | 6.893 | 10.06 | 10.011 | 0.09 | 11.11 | 13.70 | 8.596 | 11.089 | 8.556 | 11.08 | 8.513 | 11.06 | 6.076 | 8.47 | 8.424 | 0.10 | 9.41 | 11.45 | 7.447 | 9.388 | 7.409 | 9.38 | 7.368 | 9.36 | 5.479 | 7.33 | 7.282 | | | | | | | | | | | | | 0.11 | 8.14 | 9.77 | 6.588 | 8.124 | 6.553 | 8.12 | 6.513 | 8.10 | 5.027 | 6.47 | 6.430 | 0.12 | 7.174 | 8.492 | 5.926 | 7.156 | 5.893 | 7.150 | 5.856 | 7.132 | 4.671 | 5.817 | 5.776 | 0.13 | 6.413 | 7.492 | 5.403 | 6.398 | 5.371 | 6.393 | 5.336 | 6.376 | 4.383 | 5.299 | 5.260 | 0.14 | 5.804 | 6.695 | 4.979 | 5.790 | 4.950 | 5.787 | 4.917 | 5.770 | 4.144 | 4.883 | 4.845 | 0.15 | 5.307 | 6.047 | 4.629 | 5.294 | 4.603 | 5.293 | 4.572 | 5.277 | 3.942 | 4.540 | 4.504 | | | | | | | | | | | | | 0.16 | 4.894 | 5.514 | 4.335 | 4.884 | 4.311 | 4.883 | 4.283 | 4.869 | 3.766 | 4.253 | 4.219 | 0.17 | 4.547 | 5.068 | 4.084 | 4.538 | 4.063 | 4.538 | 4.036 | 4.526 | 3.612 | 4.009 | 3.976 | 0.18 | 4.251 | 4.689 | 3.867 | 4.243 | 3.847 | 4.245 | 3.824 | 4.234 | 3.474 | 3.799 | 3.768 | 0.19 | 3.995 | 4.366 | 3.676 | 3.989 | 3.659 | 3.993 | 3.638 | 3.983 | 3.349 | 3.615 | 3.586 | 0.20 | 3.771 | 4.086 | 3.506 | 3.767 | 3.492 | 3.772 | 3.473 | 3.764 | 3.234 | 3.453 | 3.426 | | | | | | | | | | | | | 0.22 | 3.399 | 3.625 | 3.217 | 3.397 | 3.207 | 3.405 | 3.193 | 3.400 | 3.030 | 3.178 | 3.154 | 0.24 | 3.099 | 3.262 | 2.976 | 3.100 | 2.971 | 3.111 | 2.961 | 3.109 | 2.851 | 2.950 | 2.930 | 0.25 | 2.969 | 3.108 | 2.869 | 2.972 | 2.866 | 2.984 | 2.858 | 2.984 | 2.769 | 2.850 | 2.831 | 0.26 | 2.850 | 2.968 | 2.769 | 2.855 | 2.768 | 2.868 | 2.763 | 2.869 | 2.690 | 2.757 | 2.740 | 0.28 | 2.639 | 2.723 | 2.589 | 2.646 | 2.592 | 2.662 | 2.590 | 2.666 | 2.544 | 2.588 | 2.574 | 0.30 | 2.455 | 2.516 | 2.428 | 2.466 | 2.434 | 2.484 | 2.436 | 2.490 | 2.410 | 2.438 | 2.428 | | | | | | | | | | | | | 0.32 | 2.294 | 2.336 | 2.282 | 2.307 | 2.293 | 2.327 | 2.298 | 2.336 | 2.285 | 2.303 | 2.296 | 0.34 | 2.149 | 2.179 | 2.150 | 2.165 | 2.163 | 2.187 | 2.172 | 2.199 | 2.169 | 2.180 | 2.176 | 0.35 | 2.083 | 2.107 | 2.088 | 2.099 | 2.103 | 2.123 | 2.113 | 2.135 | 2.114 | 2.123 | 2.120 | 0.36 | 2.019 | 2.039 | 2.029 | 2.037 | 2.045 | 2.061 | 2.056 | 2.075 | 2.061 | 2.067 | 2.066 | 0.38 | 1.900 | 1.913 | 1.917 | 1.920 | 1.935 | 1.946 | 1.949 | 1.962 | 1.959 | 1.963 | 1.964 | 0.40 | 1.791 | 1.799 | 1.813 | 1.813 | 1.833 | 1.841 | 1.849 | 1.858 | 1.864 | 1.866 | 1.869 | | | | | | | | | | | | | 0.42 | 1.691 | 1.695 | 1.716 | 1.715 | 1.739 | 1.743 | 1.756 | 1.762 | 1.774 | 1.775 | 1.781 | 0.44 | 1.598 | 1.600 | 1.626 | 1.623 | 1.650 | 1.653 | 1.670 | 1.674 | 1.690 | 1.690 | 1.697 | 0.45 | 1.554 | 1.555 | 1.583 | 1.580 | 1.608 | 1.610 | 1.628 | 1.631 | 1.649 | 1.649 | 1.658 | 0.46 | 1.512 | 1.512 | 1.542 | 1.538 | 1.567 | 1.569 | 1.588 | 1.591 | 1.610 | 1.610 | 1.619 | 0.48 | 1.432 | 1.431 | 1.463 | 1.459 | 1.489 | 1.490 | 1.512 | 1.513 | 1.535 | 1.535 | 1.546 | 0.50 | 1.357 | 1.355 | 1.389 | 1.385 | 1.416 | 1.417 | 1.440 | 1.441 | 1.464 | 1.464 | 1.476 | | | | | | | | | | | | | 0.55 | 1.190 | 1.188 | 1.223 | 1.220 | 1.252 | 1.252 | 1.277 | 1.278 | 1.303 | 1.303 | 1.319 | 0.60 | 1.049 | 1.047 | 1.081 | 1.079 | 1.111 | 1.111 | 1.137 | 1.138 | 1.163 | 1.164 | 1.182 | 0.65 | 0.928 | 0.927 | 0.959 | 0.958 | 0.989 | 0.989 | 1.015 | 1.016 | 1.042 | 1.043 | 1.061 | 0.70 | 0.825 | 0.824 | 0.855 | 0.854 | 0.883 | 0.884 | 0.910 | 0.910 | 0.935 | 0.936 | 0.956 | 0.80 | 0.660 | 0.660 | 0.687 | 0.686 | 0.713 | 0.713 | 0.737 | 0.738 | 0.761 | 0.762 | 0.782 | 0.90 | 0.538 | 0.538 | 0.561 | 0.561 | 0.583 | 0.584 | 0.605 | 0.606 | 0.627 | 0.628 | 0.646 | 1.00 | 0.447 | 0.447 | 0.466 | 0.466 | 0.485 | 0.486 | 0.504 | 0.505 | 0.523 | 0.524 | 0.541 | | | | | | | | | | | | | 1.10 | 0.377 | 0.377 | 0.393 | 0.393 | 0.409 | 0.410 | 0.425 | 0.426 | 0.441 | 0.442 | 0.457 | 1.20 | 0.323 | 0.323 | 0.336 | 0.336 | 0.350 | 0.350 | 0.364 | 0.364 | 0.378 | 0.378 | 0.391 | 1.30 | 0.281 | 0.281 | 0.291 | 0.291 | 0.303 | 0.304 | 0.315 | 0.315 | 0.327 | 0.327 | 0.339 | 1.40 | 0.246 | 0.246 | 0.256 | 0.256 | 0.265 | 0.266 | 0.275 | 0.276 | 0.286 | 0.286 | 0.296 | 1.50 | 0.219 | 0.218 | 0.226 | 0.226 | 0.235 | 0.235 | 0.243 | 0.244 | 0.252 | 0.253 | 0.261 | | | | | | | | | | | | | 1.60 | | | 0.202 | 0.202 | 0.209 | | 0.217 | | 0.224 | | 0.232 | 1.70 | | | 0.182 | 0.182 | 0.188 | | 0.195 | | 0.201 | | 0.208 | 1.80 | | | 0.164 | 0.164 | 0.170 | | 0.176 | | 0.182 | | 0.188 | 1.90 | | | 0.149 | 0.149 | 0.155 | | 0.160 | | 0.165 | | 0.170 | 2.00 | | | 0.136 | 0.136 | 0.141 | | 0.146 | | 0.150 | | 0.155 |
Element | Ga3+ | Ge4+ | Br1− | Rb1+ | Sr2+ | Y3+ | Zr4+ | Nb3+ | Nb5+ | Mo3+ | Mo5+ |
---|
Z | 31 | 32 | 35 | 37 | 38 | 39 | 40 | 41 | 41 | 42 | 42 |
---|
Method | HF | HF | RHF | RHF | RHF | *DS | *DS | *DS | *DS | *DS | *DS |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | | | 9.357 | 5.545 | 4.642 | | | | | | | 0.01 | | | −230.004 | 244.880 | 483.320 | | | | | | | 0.02 | | | −50.565 | 65.359 | 124.299 | | | | | | | 0.03 | | | −17.431 | 32.090 | 57.798 | | | | | | | 0.04 | 47.03 | 61.67 | −5.942 | 20.419 | 34.505 | 48.84 | 63.31 | 49.33 | 77.86 | 49.44 | 78.04 | 0.05 | 30.87 | 40.13 | −0.738 | 14.987 | 23.704 | 32.67 | 41.74 | 33.15 | 50.92 | 33.26 | 51.09 | | | | | | | | | | | | | 0.06 | 22.09 | 28.43 | 1.978 | 12.005 | 17.816 | 23.86 | 30.02 | 24.34 | 36.28 | 24.45 | 36.45 | 0.07 | 16.78 | 21.37 | 3.508 | 10.176 | 14.246 | 18.54 | 22.95 | 19.01 | 27.45 | 19.11 | 27.61 | 0.08 | 13.34 | 16.78 | 4.399 | 8.957 | 11.907 | 15.07 | 18.34 | 15.52 | 21.70 | 15.63 | 21.87 | 0.09 | 10.97 | 13.63 | 4.917 | 8.091 | 10.283 | 12.68 | 15.17 | 13.12 | 17.76 | 13.23 | 17.92 | 0.10 | 9.28 | 11.38 | 5.202 | 7.442 | 9.101 | 10.95 | 12.90 | 11.38 | 14.92 | 11.49 | 15.09 | | | | | | | | | | | | | 0.11 | 8.02 | 9.71 | 5.335 | 6.932 | 8.206 | 9.66 | 11.20 | 10.07 | 12.82 | 10.18 | 12.98 | 0.12 | 7.057 | 8.437 | 5.367 | 6.516 | 7.506 | 8.658 | 9.898 | 9.062 | 11.212 | 9.170 | 11.369 | 0.13 | 6.305 | 7.442 | 5.331 | 6.166 | 6.942 | 7.867 | 8.874 | 8.257 | 9.952 | 8.364 | 10.105 | 0.14 | 5.703 | 6.650 | 5.248 | 5.863 | 6.477 | 7.227 | 8.052 | 7.601 | 8.945 | 7.708 | 9.094 | 0.15 | 5.213 | 5.818 | 5.132 | 5.595 | 6.084 | 6.696 | 7.378 | 7.057 | 8.124 | 7.163 | 8.269 | | | | | | | | | | | | | 0.16 | 4.809 | 5.481 | 4.996 | 5.352 | 5.746 | 6.249 | 6.817 | 6.596 | 7.444 | 6.702 | 7.586 | 0.17 | 4.470 | 5.041 | 4.846 | 5.130 | 5.449 | 5.867 | 6.343 | 6.200 | 6.873 | 6.304 | 7.012 | 0.18 | 4.182 | 4.669 | 4.688 | 4.925 | 5.186 | 5.534 | 5.936 | 5.853 | 6.388 | 5.957 | 6.523 | 0.19 | 3.934 | 4.351 | 4.527 | 4.733 | 4.949 | 5.242 | 5.582 | 5.548 | 5.969 | 5.650 | 6.101 | 0.20 | 3.719 | 4.078 | 4.365 | 4.552 | 4.734 | 4.981 | 5.273 | 5.275 | 5.605 | 5.376 | 5.733 | | | | | | | | | | | | | 0.22 | 3.364 | 3.631 | 4.046 | 4.218 | 4.352 | 4.535 | 4.751 | 4.805 | 5.002 | 4.903 | 5.123 | 0.24 | 3.081 | 3.281 | 3.745 | 3.914 | 4.021 | 4.161 | 4.327 | 4.410 | 4.520 | 4.505 | 4.634 | 0.25 | 2.960 | 3.133 | 3.602 | 3.773 | 3.871 | 3.995 | 4.143 | 4.233 | 4.313 | 4.327 | 4.424 | 0.26 | 2.849 | 3.000 | 3.465 | 3.638 | 3.729 | 3.841 | 3.972 | 4.069 | 4.124 | 4.162 | 4.232 | 0.28 | 2.654 | 2.769 | 3.208 | 3.384 | 3.466 | 3.560 | 3.668 | 3.771 | 3.791 | 3.860 | 3.892 | 0.30 | 2.487 | 2.574 | 2.975 | 3.151 | 3.228 | 3.311 | 3.403 | 3.507 | 3.505 | 3.592 | 3.599 | | | | | | | | | | | | | 0.32 | 2.340 | 2.407 | 2.765 | 2.938 | 3.012 | 3.088 | 3.168 | 3.269 | 3.255 | 3.351 | 3.344 | 0.34 | 2.210 | 2.262 | 2.576 | 2.744 | 2.815 | 2.886 | 2.957 | 3.054 | 3.034 | 3.132 | 3.117 | 0.35 | 2.150 | 2.195 | 2.488 | 2.652 | 2.723 | 2.792 | 2.860 | 2.955 | 2.933 | 3.031 | 3.013 | 0.36 | 2.093 | 2.133 | 2.405 | 2.565 | 2.635 | 2.702 | 2.768 | 2.859 | 2.837 | 2.934 | 2.915 | 0.38 | 1.986 | 2.018 | 2.252 | 2.403 | 2.470 | 2.534 | 2.596 | 2.681 | 2.659 | 2.752 | 2.732 | 0.40 | 1.888 | 1.914 | 2.114 | 2.254 | 2.319 | 2.381 | 2.439 | 2.518 | 2.497 | 2.585 | 2.566 | | | | | | | | | | | | | 0.42 | 1.798 | 1.819 | 1.990 | 2.119 | 2.180 | 2.240 | 2.295 | 2.369 | 2.350 | 2.432 | 2.414 | 0.44 | 1.714 | 1.732 | 1.877 | 1.996 | 2.053 | 2.111 | 2.163 | 2.231 | 2.215 | 2.292 | 2.276 | 0.45 | 1.674 | 1.691 | 1.825 | 1.938 | 1.994 | 2.050 | 2.102 | 2.167 | 2.152 | 2.225 | 2.211 | 0.46 | 1.635 | 1.652 | 1.775 | 1.883 | 1.937 | 1.992 | 2.042 | 2.105 | 2.092 | 2.162 | 2.148 | 0.48 | 1.562 | 1.577 | 1.682 | 1.780 | 1.831 | 1.883 | 1.931 | 1.988 | 1.978 | 2.042 | 2.031 | 0.50 | 1.493 | 1.507 | 1.598 | 1.686 | 1.733 | 1.782 | 1.828 | 1.881 | 1.872 | 1.931 | 1.922 | | | | | | | | | | | | | 0.55 | 1.337 | 1.351 | 1.415 | 1.483 | 1.522 | 1.564 | 1.604 | 1.647 | 1.643 | 1.690 | 1.686 | 0.60 | 1.201 | 1.216 | 1.266 | 1.318 | 1.350 | 1.385 | 1.419 | 1.454 | 1.453 | 1.491 | 1.489 | 0.65 | 1.082 | 1.098 | 1.140 | 1.182 | 1.208 | 1.237 | 1.266 | 1.295 | 1.295 | 1.326 | 1.326 | 0.70 | 0.977 | 0.994 | 1.034 | 1.068 | 1.089 | 1.113 | 1.137 | 1.161 | 1.163 | 1.188 | 1.188 | 0.80 | 0.803 | 0.821 | 0.860 | 0.887 | 0.902 | 0.919 | 0.937 | 0.954 | 0.955 | 0.973 | 0.974 | 0.90 | 0.667 | 0.684 | 0.725 | 0.749 | 0.761 | 0.775 | 0.788 | 0.801 | 0.802 | 0.815 | 0.816 | 1.00 | 0.559 | 0.575 | 0.616 | 0.640 | 0.651 | 0.662 | 0.673 | 0.684 | 0.685 | 0.696 | 0.696 | | | | | | | | | | | | | 1.10 | 0.474 | 0.489 | 0.528 | 0.551 | 0.562 | 0.572 | 0.582 | 0.591 | 0.592 | 0.601 | 0.601 | 1.20 | 0.406 | 0.419 | 0.456 | 0.478 | 0.488 | 0.498 | 0.507 | 0.516 | 0.516 | 0.525 | 0.525 | 1.30 | 0.351 | 0.363 | 0.396 | 0.417 | 0.427 | 0.436 | 0.445 | 0.453 | 0.453 | 0.462 | 0.462 | 1.40 | 0.307 | 0.317 | 0.347 | 0.366 | 0.376 | 0.384 | 0.393 | 0.401 | 0.401 | 0.408 | 0.408 | 1.50 | 0.271 | 0.280 | 0.306 | 0.324 | 0.332 | 0.340 | 0.348 | 0.356 | 0.356 | 0.363 | 0.363 | | | | | | | | | | | | | 1.60 | | | 0.272 | 0.288 | 0.296 | 0.303 | 0.311 | 0.318 | 0.318 | 0.325 | 0.325 | 1.70 | | | 0.243 | 0.257 | 0.265 | 0.271 | 0.278 | 0.285 | 0.285 | 0.292 | 0.292 | 1.80 | | | 0.219 | 0.232 | 0.238 | 0.244 | 0.251 | 0.257 | 0.257 | 0.263 | 0.263 | 1.90 | | | 0.198 | 0.209 | 0.215 | 0.221 | 0.227 | 0.232 | 0.232 | 0.238 | 0.238 | 2.00 | | | 0.180 | 0.190 | 0.196 | 0.201 | 0.206 | 0.211 | 0.211 | 0.216 | 0.216 |
Element | Mo3+ | Ru3+ | Ru4+ | Rh3+ | Rh4+ | Pd2+ | Pd4+ | Ag1+ | Ag2+ | Cd2+ | In3+ |
---|
Z | 42 | 44 | 44 | 45 | 45 | 46 | 46 | 47 | 47 | 48 | 49 |
---|
Method | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | | | | | | | | | | | | 0.01 | | | | | | | | | | | | 0.02 | | | | | | | | | | | | 0.03 | | | | | | | | | | | | 0.04 | 92.49 | 49.53 | 63.83 | 49.53 | 63.87 | 35.30 | 63.89 | 21.21 | 35.23 | 35.15 | 49.41 | 0.05 | 60.17 | 33.34 | 42.27 | 33.35 | 42.31 | 24.50 | 42.32 | 15.77 | 24.43 | 24.36 | 33.23 | | | | | | | | | | | | | 0.06 | 42.61 | 24.54 | 30.54 | 24.55 | 30.58 | 18.61 | 30.61 | 12.79 | 18.54 | 18.47 | 24.43 | 0.07 | 32.01 | 19.21 | 23.46 | 19.22 | 23.50 | 15.03 | 23.52 | 10.96 | 14.97 | 14.90 | 19.11 | 0.08 | 25.13 | 15.73 | 18.85 | 15.74 | 18.89 | 12.69 | 18.92 | 9.73 | 12.63 | 12.56 | 15.65 | 0.09 | 20.40 | 13.33 | 15.68 | 13.34 | 15.72 | 11.06 | 15.75 | 8.87 | 11.00 | 10.94 | 13.26 | 0.10 | 17.02 | 11.59 | 13.39 | 11.61 | 13.44 | 9.87 | 13.46 | 8.22 | 9.82 | 9.76 | 11.53 | | | | | | | | | | | | | 0.11 | 14.50 | 10.29 | 11.69 | 10.31 | 11.74 | 8.97 | 11.76 | 7.70 | 8.92 | 8.87 | 10.24 | 0.12 | 12.585 | 9.281 | 10.381 | 9.301 | 10.430 | 8.259 | 10.458 | 7.287 | 8.217 | 8.169 | 9.249 | 0.13 | 11.086 | 8.480 | 9.351 | 8.502 | 9.399 | 7.687 | 9.431 | 6.935 | 7.652 | 7.608 | 8.463 | 0.14 | 9.891 | 7.827 | 8.521 | 7.853 | 8.571 | 7.214 | 8.603 | 6.631 | 7.184 | 7.146 | 7.826 | 0.15 | 8.919 | 7.286 | 7.840 | 7.313 | 7.891 | 6.813 | 7.924 | 6.361 | 6.789 | 6.756 | 7.299 | | | | | | | | | | | | | 0.16 | 8.118 | 6.827 | 7.271 | 6.858 | 7.322 | 6.467 | 7.357 | 6.117 | 6.448 | 6.419 | 6.856 | 0.17 | 7.449 | 6.432 | 6.788 | 6.465 | 6.841 | 6.163 | 6.877 | 5.894 | 6.149 | 6.126 | 6.476 | 0.18 | 6.881 | 6.088 | 6.372 | 6.124 | 6.426 | 5.892 | 6.464 | 5.687 | 5.883 | 5.865 | 6.147 | 0.19 | 6.395 | 5.784 | 6.011 | 5.822 | 6.065 | 5.647 | 6.105 | 5.494 | 5.643 | 5.629 | 5.858 | 0.20 | 5.975 | 5.511 | 5.692 | 5.553 | 5.747 | 5.423 | 5.788 | 5.312 | 5.424 | 5.416 | 5.600 | | | | | | | | | | | | | 0.22 | 5.283 | 5.042 | 5.153 | 5.087 | 5.211 | 5.026 | 5.255 | 4.975 | 5.036 | 5.036 | 5.158 | 0.24 | 4.739 | 4.646 | 4.712 | 4.695 | 4.771 | 4.679 | 4.818 | 4.667 | 4.697 | 4.705 | 4.786 | 0.25 | 4.508 | 4.469 | 4.519 | 4.520 | 4.578 | 4.521 | 4.626 | 4.522 | 4.541 | 4.553 | 4.621 | 0.26 | 4.297 | 4.304 | 4.340 | 4.356 | 4.400 | 4.370 | 4.449 | 4.383 | 4.394 | 4.410 | 4.466 | 0.28 | 3.931 | 4.003 | 4.020 | 4.057 | 4.080 | 4.090 | 4.130 | 4.120 | 4.121 | 4.142 | 4.184 | 0.30 | 3.620 | 3.733 | 3.738 | 3.789 | 3.799 | 3.836 | 3.850 | 3.876 | 3.871 | 3.898 | 3.930 | | | | | | | | | | | | | 0.32 | 3.352 | 3.490 | 3.488 | 3.547 | 3.548 | 3.601 | 3.601 | 3.649 | 3.640 | 3.672 | 3.701 | 0.34 | 3.118 | 3.269 | 3.263 | 3.327 | 3.323 | 3.385 | 3.376 | 3.437 | 3.427 | 3.463 | 3.490 | 0.35 | 3.011 | 3.166 | 3.158 | 3.224 | 3.218 | 3.284 | 3.271 | 3.336 | 3.327 | 3.363 | 3.390 | 0.36 | 2.910 | 3.067 | 3.058 | 3.125 | 3.118 | 3.185 | 3.171 | 3.239 | 3.230 | 3.268 | 3.295 | 0.38 | 2.725 | 2.882 | 2.872 | 2.939 | 2.931 | 3.000 | 2.984 | 3.055 | 3.046 | 3.086 | 3.115 | 0.40 | 2.557 | 2.711 | 2.702 | 2.768 | 2.759 | 2.828 | 2.812 | 2.883 | 2.875 | 2.917 | 2.947 | | | | | | | | | | | | | 0.42 | 2.406 | 2.553 | 2.545 | 2.609 | 2.601 | 2.668 | 2.653 | 2.723 | 2.716 | 2.759 | 2.790 | 0.44 | 2.267 | 2.408 | 2.400 | 2.462 | 2.454 | 2.520 | 2.505 | 2.573 | 2.567 | 2.611 | 2.643 | 0.45 | 2.202 | 2.339 | 2.332 | 2.393 | 2.385 | 2.450 | 2.436 | 2.502 | 2.497 | 2.541 | 2.574 | 0.46 | 2.140 | 2.273 | 2.266 | 2.326 | 2.319 | 2.382 | 2.369 | 2.434 | 2.429 | 2.473 | 2.506 | 0.48 | 2.024 | 2.148 | 2.143 | 2.199 | 2.193 | 2.253 | 2.242 | 2.304 | 2.300 | 2.343 | 2.378 | 0.50 | 1.916 | 2.033 | 2.028 | 2.082 | 2.077 | 2.133 | 2.124 | 2.182 | 2.179 | 2.222 | 2.258 | | | | | | | | | | | | | 0.55 | 1.682 | 1.779 | 1.776 | 1.823 | 1.820 | 1.869 | 1.863 | 1.913 | 1.912 | 1.953 | 1.989 | 0.60 | 1.487 | 1.568 | 1.567 | 1.607 | 1.606 | 1.647 | 1.644 | 1.687 | 1.686 | 1.725 | 1.760 | 0.65 | 1.325 | 1.392 | 1.392 | 1.426 | 1.426 | 1.461 | 1.460 | 1.496 | 1.496 | 1.531 | 1.564 | 0.70 | 1.189 | 1.244 | 1.244 | 1.274 | 1.274 | 1.304 | 1.304 | 1.335 | 1.335 | 1.367 | 1.397 | 0.80 | 0.975 | 1.014 | 1.015 | 1.036 | 1.037 | 1.059 | 1.060 | 1.083 | 1.083 | 1.107 | 1.132 | 0.90 | 0.817 | 0.846 | 0.846 | 0.863 | 0.863 | 0.880 | 0.880 | 0.898 | 0.898 | 0.917 | 0.936 | 1.00 | 0.696 | 0.719 | 0.720 | 0.732 | 0.732 | 0.745 | 0.746 | 0.759 | 0.759 | 0.774 | 0.789 | | | | | | | | | | | | | 1.10 | 0.602 | 0.621 | 0.621 | 0.631 | 0.631 | 0.642 | 0.642 | 0.653 | 0.653 | 0.664 | 0.676 | 1.20 | 0.525 | 0.542 | 0.542 | 0.551 | 0.551 | 0.560 | 0.560 | 0.569 | 0.569 | 0.578 | 0.588 | 1.30 | 0.462 | 0.477 | 0.477 | 0.485 | 0.485 | 0.493 | 0.493 | 0.501 | 0.501 | 0.508 | 0.516 | 1.40 | 0.409 | 0.423 | 0.423 | 0.430 | 0.430 | 0.437 | 0.437 | 0.444 | 0.444 | 0.451 | 0.458 | 1.50 | 0.363 | 0.377 | 0.377 | 0.384 | 0.384 | 0.391 | 0.391 | 0.397 | 0.397 | 0.403 | 0.409 | | | | | | | | | | | | | 1.60 | 0.325 | 0.338 | 0.338 | 0.344 | 0.344 | 0.350 | 0.350 | 0.356 | 0.356 | 0.362 | 0.368 | 1.70 | 0.292 | 0.304 | 0.304 | 0.310 | 0.310 | 0.316 | 0.316 | 0.322 | 0.322 | 0.327 | 0.332 | 1.80 | 0.263 | 0.275 | 0.275 | 0.280 | 0.280 | 0.286 | 0.286 | 0.291 | 0.291 | 0.296 | 0.301 | 1.90 | 0.238 | 0.249 | 0.249 | 0.254 | 0.254 | 0.260 | 0.260 | 0.265 | 0.265 | 0.270 | 0.274 | 2.00 | 0.216 | 0.227 | 0.227 | 0.232 | 0.232 | 0.237 | 0.237 | 0.241 | 0.241 | 0.246 | 0.251 |
Element | Sn2+ | Sn4+ | Sb3+ | Sb5+ | I1− | Cs1+ | Ba2+ | La3+ | Ce3+ | Ce4+ | Pr3+ |
---|
Z | 50 | 50 | 51 | 51 | 53 | 55 | 56 | 57 | 58 | 58 | 59 |
---|
Method | RHF | RHF | *DS | *DS | RHF | RHF | *DS | *DS | *DS | *DS | *DS |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | 6.144 | 3.971 | | | 13.835 | 9.035 | | | | | | 0.01 | 484.819 | 961.330 | | | −225.540 | 248.365 | | | | | | 0.02 | 125.792 | 243.305 | | | −46.145 | 68.827 | | | | | | 0.03 | 59.280 | 110.331 | | | −13.083 | 35.532 | | | | | | 0.04 | 35.972 | 63.782 | 50.16 | 78.38 | −1.690 | 23.823 | 37.64 | 51.70 | 51.62 | 65.94 | 51.53 | 0.05 | 25.152 | 42.227 | 33.97 | 51.44 | 3.399 | 18.344 | 26.81 | 35.49 | 35.42 | 44.36 | 35.34 | | | | | | | | | | | | | 0.06 | 19.242 | 30.510 | 25.14 | 36.81 | 5.981 | 15.307 | 20.87 | 26.65 | 26.59 | 32.62 | 26.51 | 0.07 | 15.646 | 23.435 | 19.81 | 27.97 | 7.365 | 13.414 | 17.25 | 21.30 | 21.23 | 25.51 | 21.15 | 0.08 | 13.280 | 18.833 | 16.32 | 22.22 | 8.103 | 12.124 | 14.86 | 17.78 | 17.72 | 20.87 | 17.65 | 0.09 | 11.625 | 15.668 | 13.91 | 18.28 | 8.462 | 11.180 | 13.17 | 15.34 | 15.29 | 17.66 | 15.22 | 0.10 | 10.411 | 13.395 | 12.16 | 15.45 | 8.586 | 10.448 | 11.92 | 13.57 | 13.51 | 15.34 | 13.45 | | | | | | | | | | | | | 0.11 | 9.484 | 11.703 | 10.85 | 13.35 | 8.560 | 9.851 | 10.96 | 12.22 | 12.17 | 13.60 | 12.11 | 0.12 | 8.750 | 10.407 | 9.825 | 11.743 | 8.437 | 9.345 | 10.185 | 11.163 | 11.119 | 12.258 | 11.064 | 0.13 | 8.152 | 9.388 | 9.010 | 10.486 | 8.249 | 8.903 | 9.547 | 10.313 | 10.275 | 11.185 | 10.224 | 0.14 | 7.653 | 8.571 | 8.344 | 9.480 | 8.021 | 8.506 | 9.003 | 9.610 | 9.576 | 10.312 | 9.531 | 0.15 | 7.227 | 7.902 | 7.790 | 8.660 | 7.767 | 8.143 | 8.531 | 9.016 | 8.987 | 9.586 | 8.947 | | | | | | | | | | | | | 0.16 | 6.856 | 7.345 | 7.319 | 7.982 | 7.500 | 7.806 | 8.113 | 8.505 | 8.482 | 8.972 | 8.446 | 0.17 | 6.528 | 6.875 | 6.911 | 7.413 | 7.228 | 7.491 | 7.738 | 8.056 | 8.038 | 8.441 | 8.008 | 0.18 | 6.234 | 6.473 | 6.555 | 6.928 | 6.955 | 7.193 | 7.395 | 7.658 | 7.645 | 7.979 | 7.619 | 0.19 | 5.968 | 6.124 | 6.239 | 6.512 | 6.685 | 6.911 | 7.080 | 7.300 | 7.292 | 7.569 | 7.270 | 0.20 | 5.725 | 5.818 | 5.955 | 6.149 | 6.423 | 6.643 | 6.787 | 6.974 | 6.970 | 7.202 | 6.954 | | | | | | | | | | | | | 0.22 | 5.293 | 5.304 | 5.464 | 5.548 | 5.925 | 6.143 | 6.256 | 6.398 | 6.403 | 6.568 | 6.396 | 0.24 | 4.918 | 4.886 | 5.050 | 5.067 | 5.468 | 5.688 | 5.785 | 5.900 | 5.912 | 6.033 | 5.914 | 0.25 | 4.747 | 4.703 | 4.864 | 4.860 | 5.255 | 5.475 | 5.568 | 5.674 | 5.690 | 5.794 | 5.695 | 0.26 | 4.586 | 4.535 | 4.691 | 4.671 | 5.054 | 5.272 | 5.362 | 5.461 | 5.480 | 5.570 | 5.489 | 0.28 | 4.289 | 4.232 | 4.375 | 4.336 | 4.681 | 4.893 | 4.980 | 5.069 | 5.094 | 5.163 | 5.109 | 0.30 | 4.021 | 3.967 | 4.094 | 4.048 | 4.348 | 4.549 | 4.633 | 4.716 | 4.745 | 4.800 | 4.766 | | | | | | | | | | | | | 0.32 | 3.778 | 3.730 | 3.840 | 3.793 | 4.049 | 4.237 | 4.318 | 4.396 | 4.429 | 4.474 | 4.454 | 0.34 | 3.556 | 3.516 | 3.611 | 3.567 | 3.782 | 3.954 | 4.032 | 4.106 | 4.142 | 4.179 | 4.170 | 0.35 | 3.452 | 3.416 | 3.503 | 3.463 | 3.658 | 3.823 | 3.899 | 3.971 | 4.008 | 4.042 | 4.037 | 0.36 | 3.352 | 3.320 | 3.401 | 3.363 | 3.541 | 3.698 | 3.772 | 3.843 | 3.880 | 3.911 | 3.910 | 0.38 | 3.164 | 3.140 | 3.208 | 3.177 | 3.325 | 3.466 | 3.536 | 3.602 | 3.640 | 3.667 | 3.673 | 0.40 | 2.991 | 2.973 | 3.031 | 3.006 | 3.129 | 3.255 | 3.321 | 3.383 | 3.422 | 3.444 | 3.455 | | | | | | | | | | | | | 0.42 | 2.830 | 2.817 | 2.867 | 2.848 | 2.951 | 3.064 | 3.124 | 3.183 | 3.221 | 3.240 | 3.255 | 0.44 | 2.680 | 2.672 | 2.716 | 2.702 | 2.789 | 2.890 | 2.946 | 3.000 | 3.038 | 3.054 | 3.072 | 0.45 | 2.610 | 2.604 | 2.644 | 2.632 | 2.714 | 2.808 | 2.862 | 2.914 | 2.952 | 2.967 | 2.986 | 0.46 | 2.541 | 2.537 | 2.575 | 2.565 | 2.641 | 2.731 | 2.782 | 2.832 | 2.870 | 2.883 | 2.904 | 0.48 | 2.412 | 2.410 | 2.444 | 2.438 | 2.505 | 2.586 | 2.632 | 2.679 | 2.715 | 2.726 | 2.749 | 0.50 | 2.290 | 2.291 | 2.322 | 2.319 | 2.379 | 2.452 | 2.495 | 2.538 | 2.573 | 2.582 | 2.606 | | | | | | | | | | | | | 0.55 | 2.020 | 2.023 | 2.050 | 2.051 | 2.103 | 2.163 | 2.197 | 2.232 | 2.264 | 2.268 | 2.295 | 0.60 | 1.791 | 1.794 | 1.819 | 1.822 | 1.871 | 1.923 | 1.951 | 1.980 | 2.010 | 2.011 | 2.038 | 0.65 | 1.594 | 1.597 | 1.622 | 1.625 | 1.673 | 1.721 | 1.745 | 1.770 | 1.797 | 1.796 | 1.823 | 0.70 | 1.426 | 1.428 | 1.453 | 1.455 | 1.503 | 1.548 | 1.570 | 1.592 | 1.617 | 1.615 | 1.641 | 0.80 | 1.157 | 1.157 | 1.181 | 1.182 | 1.227 | 1.269 | 1.288 | 1.307 | 1.328 | 1.326 | 1.349 | 0.90 | 0.956 | 0.956 | 0.976 | 0.977 | 1.017 | 1.055 | 1.072 | 1.090 | 1.108 | 1.107 | 1.126 | 1.00 | 0.805 | 0.804 | 0.821 | 0.821 | 0.855 | 0.888 | 0.904 | 0.920 | 0.936 | 0.935 | 0.952 | | | | | | | | | | | | | 1.10 | 0.688 | 0.688 | 0.702 | 0.702 | 0.729 | 0.757 | 0.771 | 0.785 | 0.799 | 0.799 | 0.813 | 1.20 | 0.597 | 0.597 | 0.608 | 0.608 | 0.630 | 0.654 | 0.666 | 0.678 | 0.690 | 0.690 | 0.702 | 1.30 | 0.525 | 0.524 | 0.534 | 0.533 | 0.551 | 0.571 | 0.581 | 0.591 | 0.602 | 0.602 | 0.612 | 1.40 | 0.465 | 0.465 | 0.473 | 0.473 | 0.487 | 0.504 | 0.512 | 0.521 | 0.530 | 0.530 | 0.539 | 1.50 | 0.416 | 0.416 | 0.422 | 0.422 | 0.435 | 0.448 | 0.456 | 0.463 | 0.471 | 0.471 | 0.478 | | | | | | | | | | | | | 1.60 | 0.374 | 0.374 | 0.379 | 0.379 | 0.391 | 0.402 | 0.409 | 0.415 | 0.421 | 0.421 | 0.428 | 1.70 | 0.338 | 0.338 | 0.343 | 0.343 | 0.353 | 0.364 | 0.369 | 0.374 | 0.380 | 0.380 | 0.386 | 1.80 | 0.306 | 0.306 | 0.311 | 0.311 | 0.321 | 0.330 | 0.335 | 0.340 | 0.345 | 0.345 | 0.350 | 1.90 | 0.279 | 0.279 | 0.284 | 0.284 | 0.293 | 0.301 | 0.306 | 0.310 | 0.314 | 0.314 | 0.319 | 2.00 | 0.255 | 0.255 | 0.259 | 0.259 | 0.268 | 0.276 | 0.280 | 0.284 | 0.288 | 0.288 | 0.292 |
Element | Pr4+ | Nd3+ | Pm3+ | Sm3+ | Eu2+ | Eu3+ | Gd3+ | Tb3+ | Dy3+ | Ho3+ | Er3+ |
---|
Z | 59 | 60 | 61 | 62 | 63 | 63 | 64 | 65 | 66 | 67 | 68 |
---|
Method | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | | | | | | | | | | | | 0.01 | | | | | | | | | | | | 0.02 | | | | | | | | | | | | 0.03 | | | | | | | | | | | | 0.04 | 65.86 | 51.44 | 51.35 | 51.26 | 36.99 | 51.17 | 51.08 | 51.04 | 50.92 | 50.83 | 50.74 | 0.05 | 44.30 | 35.25 | 35.15 | 35.07 | 26.17 | 34.97 | 34.90 | 34.85 | 34.72 | 34.64 | 34.55 | | | | | | | | | | | | | 0.06 | 32.55 | 26.42 | 26.33 | 26.25 | 20.26 | 26.15 | 26.08 | 26.02 | 25.92 | 25.83 | 25.74 | 0.07 | 25.44 | 21.07 | 20.98 | 20.90 | 16.67 | 20.81 | 20.74 | 20.68 | 20.58 | 20.50 | 20.41 | 0.08 | 20.81 | 17.57 | 17.49 | 17.41 | 14.30 | 17.32 | 17.25 | 17.19 | 17.09 | 17.01 | 16.93 | 0.09 | 17.60 | 15.14 | 15.06 | 14.98 | 12.65 | 14.90 | 14.83 | 14.77 | 14.68 | 14.60 | 14.53 | 0.10 | 15.29 | 13.38 | 13.30 | 13.23 | 11.44 | 13.15 | 13.08 | 13.02 | 12.94 | 12.86 | 12.79 | | | | | | | | | | | | | 0.11 | 13.55 | 12.04 | 11.97 | 11.90 | 10.51 | 11.83 | 11.76 | 11.71 | 11.62 | 11.55 | 11.48 | 0.12 | 12.210 | 11.003 | 10.937 | 10.870 | 9.770 | 10.802 | 10.739 | 10.681 | 10.604 | 10.538 | 10.469 | 0.13 | 11.141 | 10.167 | 10.106 | 10.044 | 9.167 | 9.979 | 9.919 | 9.863 | 9.792 | 9.728 | 9.664 | 0.14 | 10.272 | 9.480 | 9.422 | 9.366 | 8.663 | 9.305 | 9.248 | 9.194 | 9.128 | 9.068 | 9.007 | 0.15 | 9.550 | 8.901 | 8.849 | 8.796 | 8.229 | 8.740 | 8.686 | 8.634 | 8.574 | 8.517 | 8.460 | | | | | | | | | | | | | 0.16 | 8.939 | 8.405 | 8.357 | 8.310 | 7.850 | 8.257 | 8.207 | 8.158 | 8.102 | 8.049 | 7.995 | 0.17 | 8.413 | 7.972 | 7.930 | 7.886 | 7.511 | 7.838 | 7.791 | 7.746 | 7.694 | 7.645 | 7.594 | 0.18 | 7.955 | 7.589 | 7.551 | 7.512 | 7.206 | 7.468 | 7.425 | 7.383 | 7.335 | 7.290 | 7.242 | 0.19 | 7.549 | 7.245 | 7.212 | 7.177 | 6.927 | 7.138 | 7.099 | 7.059 | 7.016 | 6.974 | 6.930 | 0.20 | 7.187 | 6.932 | 6.904 | 6.874 | 6.669 | 6.839 | 6.804 | 6.768 | 6.729 | 6.690 | 6.650 | | | | | | | | | | | | | 0.22 | 6.561 | 6.384 | 6.364 | 6.342 | 6.204 | 6.316 | 6.289 | 6.258 | 6.227 | 6.196 | 6.162 | 0.24 | 6.033 | 5.910 | 5.899 | 5.884 | 5.792 | 5.865 | 5.845 | 5.822 | 5.798 | 5.773 | 5.745 | 0.25 | 5.797 | 5.695 | 5.687 | 5.677 | 5.601 | 5.661 | 5.645 | 5.625 | 5.604 | 5.582 | 5.557 | 0.26 | 5.577 | 5.492 | 5.488 | 5.481 | 5.419 | 5.469 | 5.456 | 5.439 | 5.421 | 5.402 | 5.380 | 0.28 | 5.176 | 5.118 | 5.121 | 5.120 | 5.080 | 5.115 | 5.107 | 5.096 | 5.085 | 5.071 | 5.055 | 0.30 | 4.818 | 4.780 | 4.789 | 4.793 | 4.768 | 4.794 | 4.792 | 4.787 | 4.780 | 4.772 | 4.760 | | | | | | | | | | | | | 0.32 | 4.496 | 4.473 | 4.486 | 4.496 | 4.482 | 4.501 | 4.504 | 4.504 | 4.502 | 4.498 | 4.492 | 0.34 | 4.205 | 4.193 | 4.210 | 4.224 | 4.218 | 4.233 | 4.240 | 4.244 | 4.247 | 4.247 | 4.244 | 0.35 | 4.069 | 4.061 | 4.081 | 4.096 | 4.093 | 4.107 | 4.116 | 4.122 | 4.126 | 4.128 | 4.128 | 0.36 | 3.939 | 3.936 | 3.956 | 3.973 | 3.973 | 3.987 | 3.997 | 4.005 | 4.011 | 4.014 | 4.016 | 0.38 | 3.697 | 3.700 | 3.724 | 3.743 | 3.748 | 3.759 | 3.773 | 3.784 | 3.793 | 3.799 | 3.804 | 0.40 | 3.476 | 3.484 | 3.509 | 3.531 | 3.540 | 3.550 | 3.566 | 3.579 | 3.590 | 3.600 | 3.607 | | | | | | | | | | | | | 0.42 | 3.273 | 3.285 | 3.312 | 3.335 | 3.347 | 3.356 | 3.374 | 3.389 | 3.403 | 3.414 | 3.423 | 0.44 | 3.087 | 3.103 | 3.130 | 3.155 | 3.168 | 3.176 | 3.196 | 3.213 | 3.228 | 3.241 | 3.253 | 0.45 | 3.000 | 3.017 | 3.045 | 3.069 | 3.084 | 3.092 | 3.112 | 3.130 | 3.146 | 3.160 | 3.172 | 0.46 | 2.916 | 2.934 | 2.962 | 2.988 | 3.003 | 3.010 | 3.031 | 3.049 | 3.066 | 3.081 | 3.094 | 0.48 | 2.759 | 2.779 | 2.807 | 2.833 | 2.850 | 2.856 | 2.878 | 2.897 | 2.915 | 2.931 | 2.945 | 0.50 | 2.614 | 2.636 | 2.664 | 2.690 | 2.709 | 2.714 | 2.736 | 2.756 | 2.775 | 2.791 | 2.807 | | | | | | | | | | | | | 0.55 | 2.299 | 2.324 | 2.351 | 2.376 | 2.397 | 2.400 | 2.423 | 2.444 | 2.463 | 2.481 | 2.498 | 0.60 | 2.040 | 2.065 | 2.091 | 2.115 | 2.137 | 2.138 | 2.160 | 2.181 | 2.201 | 2.220 | 2.237 | 0.65 | 1.823 | 1.848 | 1.872 | 1.895 | 1.917 | 1.917 | 1.939 | 1.959 | 1.978 | 1.997 | 2.014 | 0.70 | 1.639 | 1.664 | 1.686 | 1.708 | 1.730 | 1.729 | 1.749 | 1.769 | 1.788 | 1.806 | 1.823 | 0.80 | 1.347 | 1.369 | 1.389 | 1.408 | 1.428 | 1.427 | 1.445 | 1.463 | 1.480 | 1.497 | 1.513 | 0.90 | 1.125 | 1.144 | 1.162 | 1.179 | 1.197 | 1.196 | 1.212 | 1.228 | 1.244 | 1.260 | 1.274 | 1.00 | 0.951 | 0.968 | 0.984 | 0.999 | 1.015 | 1.014 | 1.029 | 1.044 | 1.058 | 1.072 | 1.086 | | | | | | | | | | | | | 1.10 | 0.813 | 0.827 | 0.841 | 0.855 | 0.869 | 0.869 | 0.882 | 0.895 | 0.908 | 0.921 | 0.934 | 1.20 | 0.702 | 0.714 | 0.727 | 0.739 | 0.751 | 0.751 | 0.763 | 0.775 | 0.787 | 0.798 | 0.810 | 1.30 | 0.612 | 0.623 | 0.634 | 0.644 | 0.655 | 0.655 | 0.666 | 0.676 | 0.687 | 0.697 | 0.708 | 1.40 | 0.539 | 0.548 | 0.557 | 0.567 | 0.576 | 0.576 | 0.585 | 0.595 | 0.604 | 0.613 | 0.623 | 1.50 | 0.478 | 0.486 | 0.494 | 0.502 | 0.510 | 0.510 | 0.519 | 0.527 | 0.535 | 0.544 | 0.552 | | | | | | | | | | | | | 1.60 | 0.428 | 0.435 | 0.442 | 0.449 | 0.456 | 0.456 | 0.463 | 0.470 | 0.478 | 0.485 | 0.492 | 1.70 | 0.386 | 0.392 | 0.398 | 0.404 | 0.410 | 0.410 | 0.416 | 0.423 | 0.429 | 0.436 | 0.442 | 1.80 | 0.350 | 0.355 | 0.360 | 0.366 | 0.371 | 0.371 | 0.377 | 0.382 | 0.388 | 0.394 | 0.399 | 1.90 | 0.319 | 0.324 | 0.328 | 0.333 | 0.338 | 0.338 | 0.343 | 0.348 | 0.353 | 0.358 | 0.363 | 2.00 | 0.292 | 0.296 | 0.301 | 0.305 | 0.309 | 0.309 | 0.313 | 0.318 | 0.322 | 0.327 | 0.331 |
Element | Tm3+ | Yb2+ | Yb3+ | Lu3+ | Hf4+ | Ta5+ | W6+ | Os4+ | Ir3+ | Ir4+ | Pt2+ |
---|
Z | 69 | 70 | 70 | 71 | 72 | 73 | 74 | 76 | 77 | 77 | 78 |
---|
Method | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | | | | | | | | | | | | 0.01 | | | | | | | | | | | | 0.02 | | | | | | | | | | | | 0.03 | | | | | | | | | | | | 0.04 | 50.67 | 36.30 | 50.58 | 50.50 | 64.91 | 79.42 | 94.00 | 65.56 | 51.44 | 65.65 | 37.41 | 0.05 | 34.47 | 25.49 | 34.40 | 34.32 | 43.35 | 52.47 | 61.68 | 44.00 | 35.25 | 44.09 | 26.60 | | | | | | | | | | | | | 0.06 | 25.67 | 19.61 | 25.59 | 25.52 | 31.63 | 37.84 | 44.11 | 32.26 | 26.43 | 32.36 | 20.68 | 0.07 | 20.34 | 16.03 | 20.27 | 20.19 | 24.54 | 28.99 | 33.51 | 25.17 | 21.09 | 25.26 | 17.09 | 0.08 | 16.86 | 13.68 | 16.79 | 16.72 | 19.93 | 23.24 | 26.62 | 20.55 | 17.60 | 20.64 | 14.72 | 0.09 | 14.46 | 12.05 | 14.39 | 14.32 | 16.76 | 19.29 | 21.89 | 17.36 | 15.18 | 17.45 | 13.06 | 0.10 | 12.72 | 10.86 | 12.65 | 12.59 | 14.47 | 16.45 | 18.50 | 15.06 | 13.42 | 15.15 | 11.84 | | | | | | | | | | | | | 0.11 | 11.42 | 9.95 | 11.35 | 11.29 | 12.77 | 14.34 | 15.98 | 13.34 | 12.10 | 13.43 | 10.91 | 0.12 | 10.406 | 9.243 | 10.343 | 10.282 | 11.463 | 12.727 | 14.051 | 12.019 | 11.071 | 12.108 | 10.170 | 0.13 | 9.603 | 8.669 | 9.542 | 9.484 | 10.432 | 11.460 | 12.545 | 10.971 | 10.248 | 11.061 | 9.567 | 0.14 | 8.950 | 8.191 | 8.891 | 8.835 | 9.600 | 10.443 | 11.341 | 10.122 | 9.571 | 10.211 | 9.058 | 0.15 | 8.405 | 7.788 | 8.349 | 8.296 | 8.918 | 9.613 | 10.361 | 9.421 | 9.006 | 9.510 | 8.623 | | | | | | | | | | | | | 0.16 | 7.943 | 7.436 | 7.890 | 7.839 | 8.348 | 8.924 | 9.550 | 8.833 | 8.523 | 8.919 | 8.241 | 0.17 | 7.545 | 7.128 | 7.495 | 7.447 | 7.863 | 8.343 | 8.870 | 8.330 | 8.104 | 8.415 | 7.902 | 0.18 | 7.196 | 6.852 | 7.150 | 7.104 | 7.445 | 7.847 | 8.292 | 7.895 | 7.734 | 7.978 | 7.595 | 0.19 | 6.888 | 6.601 | 6.843 | 6.801 | 7.081 | 7.418 | 7.795 | 7.512 | 7.404 | 7.594 | 7.314 | 0.20 | 6.610 | 6.372 | 6.569 | 6.529 | 6.760 | 7.042 | 7.364 | 7.172 | 7.107 | 7.253 | 7.055 | | | | | | | | | | | | | 0.22 | 6.128 | 5.962 | 6.093 | 6.058 | 6.214 | 6.415 | 6.650 | 6.591 | 6.585 | 6.668 | 6.587 | 0.24 | 5.717 | 5.601 | 5.688 | 5.659 | 5.765 | 5.907 | 6.080 | 6.107 | 6.138 | 6.181 | 6.173 | 0.25 | 5.532 | 5.434 | 5.505 | 5.479 | 5.566 | 5.687 | 5.836 | 5.893 | 5.936 | 5.965 | 5.981 | 0.26 | 5.358 | 5.276 | 5.334 | 5.310 | 5.382 | 5.485 | 5.613 | 5.693 | 5.745 | 5.764 | 5.799 | 0.28 | 5.038 | 4.980 | 5.019 | 5.000 | 5.049 | 5.124 | 5.220 | 5.331 | 5.395 | 5.398 | 5.458 | 0.30 | 4.748 | 4.708 | 4.734 | 4.720 | 4.754 | 4.809 | 4.882 | 5.009 | 5.078 | 5.072 | 5.145 | | | | | | | | | | | | | 0.32 | 4.484 | 4.456 | 4.474 | 4.464 | 4.489 | 4.530 | 4.586 | 4.719 | 4.789 | 4.779 | 4.857 | 0.34 | 4.240 | 4.221 | 4.234 | 4.228 | 4.247 | 4.279 | 4.323 | 4.456 | 4.524 | 4.512 | 4.590 | 0.35 | 4.126 | 4.110 | 4.122 | 4.117 | 4.134 | 4.162 | 4.201 | 4.333 | 4.400 | 4.387 | 4.464 | 0.36 | 4.015 | 4.003 | 4.013 | 4.010 | 4.025 | 4.051 | 4.086 | 4.215 | 4.280 | 4.267 | 4.343 | 0.38 | 3.806 | 3.800 | 3.807 | 3.807 | 3.821 | 3.843 | 3.872 | 3.994 | 4.055 | 4.042 | 4.114 | 0.40 | 3.612 | 3.609 | 3.616 | 3.618 | 3.632 | 3.650 | 3.675 | 3.789 | 3.845 | 3.834 | 3.900 | | | | | | | | | | | | | 0.42 | 3.431 | 3.432 | 3.437 | 3.442 | 3.455 | 3.473 | 3.495 | 3.599 | 3.651 | 3.641 | 3.702 | 0.44 | 3.262 | 3.266 | 3.271 | 3.277 | 3.291 | 3.307 | 3.327 | 3.423 | 3.471 | 3.462 | 3.518 | 0.45 | 3.182 | 3.187 | 3.191 | 3.199 | 3.213 | 3.229 | 3.248 | 3.340 | 3.385 | 3.377 | 3.430 | 0.46 | 3.105 | 3.110 | 3.115 | 3.123 | 3.137 | 3.153 | 3.172 | 3.259 | 3.303 | 3.295 | 3.346 | 0.48 | 2.958 | 2.965 | 2.969 | 2.979 | 2.993 | 3.009 | 3.027 | 3.106 | 3.146 | 3.140 | 3.186 | 0.50 | 2.820 | 2.829 | 2.833 | 2.844 | 2.859 | 2.875 | 2.892 | 2.963 | 3.000 | 2.995 | 3.036 | | | | | | | | | | | | | 0.55 | 2.514 | 2.526 | 2.528 | 2.541 | 2.557 | 2.573 | 2.590 | 2.646 | 2.675 | 2.672 | 2.704 | 0.60 | 2.253 | 2.267 | 2.269 | 2.283 | 2.299 | 2.315 | 2.331 | 2.375 | 2.399 | 2.398 | 2.423 | 0.65 | 2.031 | 2.046 | 2.047 | 2.061 | 2.077 | 2.092 | 2.108 | 2.144 | 2.164 | 2.164 | 2.184 | 0.70 | 1.839 | 1.855 | 1.855 | 1.870 | 1.885 | 1.900 | 1.914 | 1.945 | 1.962 | 1.962 | 1.979 | 0.80 | 1.529 | 1.544 | 1.544 | 1.558 | 1.572 | 1.585 | 1.598 | 1.623 | 1.636 | 1.636 | 1.649 | 0.90 | 1.289 | 1.304 | 1.303 | 1.317 | 1.329 | 1.341 | 1.353 | 1.375 | 1.386 | 1.386 | 1.397 | 1.00 | 1.099 | 1.113 | 1.112 | 1.125 | 1.137 | 1.148 | 1.159 | 1.179 | 1.189 | 1.189 | 1.199 | | | | | | | | | | | | | 1.10 | 0.946 | 0.959 | 0.958 | 0.970 | 0.981 | 0.992 | 1.002 | 1.021 | 1.031 | 1.031 | 1.040 | 1.20 | 0.821 | 0.833 | 0.832 | 0.843 | 0.854 | 0.864 | 0.873 | 0.892 | 0.901 | 0.901 | 0.909 | 1.30 | 0.718 | 0.728 | 0.728 | 0.738 | 0.748 | 0.757 | 0.766 | 0.784 | 0.792 | 0.792 | 0.800 | 1.40 | 0.632 | 0.641 | 0.641 | 0.650 | 0.659 | 0.668 | 0.677 | 0.693 | 0.701 | 0.701 | 0.709 | 1.50 | 0.560 | 0.569 | 0.569 | 0.577 | 0.585 | 0.593 | 0.601 | 0.616 | 0.624 | 0.624 | 0.631 | | | | | | | | | | | | | 1.60 | 0.500 | 0.507 | 0.507 | 0.515 | 0.522 | 0.529 | 0.537 | 0.551 | 0.558 | 0.558 | 0.565 | 1.70 | 0.449 | 0.455 | 0.455 | 0.462 | 0.469 | 0.475 | 0.482 | 0.495 | 0.502 | 0.502 | 0.508 | 1.80 | 0.405 | 0.411 | 0.411 | 0.417 | 0.423 | 0.429 | 0.435 | 0.447 | 0.453 | 0.453 | 0.459 | 1.90 | 0.368 | 0.373 | 0.373 | 0.379 | 0.384 | 0.389 | 0.395 | 0.405 | 0.411 | 0.411 | 0.416 | 2.00 | 0.336 | 0.341 | 0.341 | 0.345 | 0.350 | 0.355 | 0.360 | 0.370 | 0.374 | 0.374 | 0.379 |
Element | Pt4+ | Au1+ | Au3+ | Hg1+ | Hg2+ | Tl1+ | Tl3+ | Pb2+ | Pb4+ | Bi3+ | Bi5+ |
---|
Z | 78 | 79 | 79 | 80 | 80 | 81 | 81 | 82 | 82 | 83 | 83 |
---|
Method | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS | *DS |
---|
(sin )/λ (Å−1) | | | | | | | | | | | |
---|
0.00 | | | | | | | | | | | | 0.01 | | | | | | | | | | | | 0.02 | | | | | | | | | | | | 0.03 | | | | | | | | | | | | 0.04 | 65.73 | 23.52 | 51.50 | 23.84 | 37.35 | 24.11 | 51.46 | 37.98 | 65.83 | 52.12 | 80.28 | 0.05 | 44.16 | 18.07 | 35.32 | 18.38 | 26.53 | 18.65 | 35.29 | 27.15 | 44.27 | 35.91 | 53.34 | | | | | | | | | | | | | 0.06 | 32.42 | 15.05 | 26.49 | 15.36 | 20.63 | 15.62 | 26.48 | 21.23 | 32.54 | 27.09 | 38.69 | 0.07 | 25.33 | 13.19 | 21.15 | 13.49 | 17.04 | 13.74 | 21.15 | 17.62 | 25.45 | 21.74 | 29.85 | 0.08 | 20.71 | 11.94 | 17.67 | 12.23 | 14.67 | 12.47 | 17.67 | 15.24 | 20.83 | 18.23 | 24.09 | 0.09 | 17.52 | 11.04 | 15.25 | 11.31 | 13.03 | 11.54 | 15.26 | 13.57 | 17.65 | 15.81 | 20.13 | 0.10 | 15.22 | 10.35 | 13.50 | 10.60 | 11.82 | 10.83 | 13.51 | 12.34 | 15.35 | 14.04 | 17.29 | | | | | | | | | | | | | 0.11 | 13.50 | 9.80 | 12.18 | 10.04 | 10.89 | 10.26 | 12.20 | 11.40 | 13.64 | 12.70 | 15.17 | 0.12 | 12.178 | 9.341 | 11.153 | 9.565 | 10.165 | 9.775 | 11.178 | 10.642 | 12.316 | 11.663 | 13.539 | 0.13 | 11.130 | 8.946 | 10.331 | 9.156 | 9.569 | 9.356 | 10.362 | 10.024 | 11.272 | 10.827 | 12.262 | 0.14 | 10.281 | 8.599 | 9.660 | 8.795 | 9.072 | 8.983 | 9.696 | 9.500 | 10.427 | 10.138 | 11.234 | 0.15 | 9.579 | 8.285 | 9.097 | 8.466 | 8.644 | 8.645 | 9.139 | 9.049 | 9.730 | 9.559 | 10.392 | | | | | | | | | | | | | 0.16 | 8.988 | 7.997 | 8.617 | 8.166 | 8.271 | 8.335 | 8.664 | 8.653 | 9.144 | 9.061 | 9.690 | 0.17 | 8.484 | 7.731 | 8.201 | 7.887 | 7.940 | 8.045 | 8.253 | 8.297 | 8.644 | 8.629 | 9.097 | 0.18 | 8.047 | 7.480 | 7.834 | 7.624 | 7.640 | 7.773 | 7.890 | 7.975 | 8.211 | 8.245 | 8.587 | 0.19 | 7.662 | 7.243 | 7.506 | 7.376 | 7.367 | 7.516 | 7.567 | 7.679 | 7.830 | 7.901 | 8.144 | 0.20 | 7.320 | 7.018 | 7.211 | 7.141 | 7.114 | 7.272 | 7.275 | 7.406 | 7.492 | 7.589 | 7.755 | | | | | | | | | | | | | 0.22 | 6.735 | 6.598 | 6.693 | 6.703 | 6.658 | 6.817 | 6.765 | 6.912 | 6.913 | 7.040 | 7.100 | 0.24 | 6.246 | 6.210 | 6.247 | 6.301 | 6.253 | 6.400 | 6.326 | 6.472 | 6.429 | 6.566 | 6.564 | 0.25 | 6.029 | 6.028 | 6.046 | 6.112 | 6.065 | 6.205 | 6.127 | 6.268 | 6.214 | 6.351 | 6.329 | 0.26 | 5.827 | 5.852 | 5.855 | 5.930 | 5.886 | 6.017 | 5.939 | 6.075 | 6.014 | 6.148 | 6.111 | 0.28 | 5.459 | 5.519 | 5.505 | 5.587 | 5.550 | 5.664 | 5.591 | 5.714 | 5.647 | 5.773 | 5.721 | 0.30 | 5.131 | 5.209 | 5.186 | 5.270 | 5.240 | 5.337 | 5.275 | 5.383 | 5.320 | 5.433 | 5.377 | | | | | | | | | | | | | 0.32 | 4.385 | 4.921 | 4.895 | 4.975 | 4.953 | 5.035 | 4.985 | 5.078 | 5.023 | 5.123 | 5.069 | 0.34 | 4.565 | 4.652 | 4.627 | 4.702 | 4.686 | 4.756 | 4.718 | 4.797 | 4.751 | 4.838 | 4.790 | 0.35 | 4.439 | 4.525 | 4.501 | 4.573 | 4.560 | 4.624 | 4.591 | 4.664 | 4.623 | 4.704 | 4.660 | 0.36 | 4.318 | 4.402 | 4.379 | 4.448 | 4.437 | 4.497 | 4.469 | 4.536 | 4.501 | 4.576 | 4.535 | 0.38 | 4.090 | 4.170 | 4.149 | 4.212 | 4.206 | 4.257 | 4.238 | 4.295 | 4.269 | 4.333 | 4.300 | 0.40 | 3.880 | 3.953 | 3.936 | 3.993 | 3.990 | 4.034 | 4.022 | 4.072 | 4.053 | 4.108 | 4.083 | | | | | | | | | | | | | 0.42 | 3.684 | 3.752 | 3.737 | 3.789 | 3.788 | 3.827 | 3.821 | 3.864 | 3.851 | 3.899 | 3.881 | 0.44 | 3.502 | 3.564 | 3.552 | 3.599 | 3.600 | 3.635 | 3.633 | 3.671 | 3.663 | 3.705 | 3.692 | 0.45 | 3.416 | 3.475 | 3.464 | 3.509 | 3.511 | 3.544 | 3.544 | 3.579 | 3.574 | 3.613 | 3.603 | 0.46 | 3.333 | 3.389 | 3.379 | 3.422 | 3.424 | 3.456 | 3.457 | 3.491 | 3.488 | 3.524 | 3.516 | 0.48 | 3.176 | 3.225 | 3.218 | 3.258 | 3.260 | 3.290 | 3.293 | 3.323 | 3.323 | 3.355 | 3.351 | 0.50 | 3.028 | 3.073 | 3.068 | 3.104 | 3.107 | 3.134 | 3.139 | 3.166 | 3.168 | 3.197 | 3.197 | | | | | | | | | | | | | 0.55 | 2.700 | 2.735 | 2.733 | 2.762 | 2.765 | 2.790 | 2.795 | 2.819 | 2.823 | 2.847 | 2.850 | 0.60 | 2.422 | 2.449 | 2.448 | 2.474 | 2.476 | 2.498 | 2.502 | 2.524 | 2.528 | 2.549 | 2.554 | 0.96 | 2.184 | 2.206 | 2.206 | 2.227 | 2.229 | 2.249 | 2.252 | 2.272 | 2.276 | 2.295 | 2.300 | 0.70 | 1.980 | 1.998 | 1.998 | 2.017 | 2.017 | 2.036 | 2.038 | 2.057 | 2.059 | 2.077 | 2.080 | 0.80 | 1.650 | 1.663 | 1.663 | 1.678 | 1.678 | 1.693 | 1.694 | 1.709 | 1.710 | 1.726 | 1.727 | 0.90 | 1.397 | 1.408 | 1.408 | 1.420 | 1.420 | 1.432 | 1.432 | 1.445 | 1.445 | 1.458 | 1.458 | 1.00 | 1.199 | 1.208 | 1.209 | 1.218 | 1.218 | 1.229 | 1.228 | 1.239 | 1.239 | 1.250 | 1.249 | | | | | | | | | | | | | 1.10 | 1.040 | 1.048 | 1.048 | 1.057 | 1.057 | 1.066 | 1.066 | 1.075 | 1.075 | 1.084 | 1.084 | 1.20 | 0.909 | 0.917 | 0.917 | 0.926 | 0.925 | 0.934 | 0.933 | 0.942 | 0.941 | 0.950 | 0.949 | 1.30 | 0.800 | 0.808 | 0.808 | 0.816 | 0.816 | 0.824 | 0.824 | 0.831 | 0.831 | 0.838 | 0.838 | 1.40 | 0.709 | 0.717 | 0.716 | 0.724 | 0.724 | 0.731 | 0.731 | 0.738 | 0.738 | 0.745 | 0.745 | 1.50 | 0.631 | 0.638 | 0.638 | 0.645 | 0.645 | 0.652 | 0.652 | 0.659 | 0.659 | 0.665 | 0.665 | | | | | | | | | | | | | 1.60 | 0.565 | 0.572 | 0.572 | 0.578 | 0.578 | 0.585 | 0.585 | 0.591 | 0.591 | 0.597 | 0.597 | 1.70 | 0.508 | 0.514 | 0.514 | 0.520 | 0.520 | 0.526 | 0.527 | 0.532 | 0.533 | 0.538 | 0.538 | 1.80 | 0.459 | 0.465 | 0.465 | 0.470 | 0.470 | 0.476 | 0.476 | 0.482 | 0.482 | 0.487 | 0.487 | 1.90 | 0.416 | 0.422 | 0.422 | 0.427 | 0.427 | 0.432 | 0.432 | 0.438 | 0.438 | 0.443 | 0.443 | 2.00 | 0.379 | 0.384 | 0.384 | 0.389 | 0.389 | 0.394 | 0.394 | 0.399 | 0.399 | 0.404 | 0.404 |
Element | Ra2+ | Ac3+ | U3+ | U4+ | U6+ |
---|
Z | 88 | 89 | 92 | 92 | 92 |
---|
Method | *DS | *DS | *DS | *DS | *DS |
---|
(sin )λ (Å−1) | | | | | |
---|
0.00 | | | | | | 0.01 | | | | | | 0.02 | | | | | | 0.03 | | | | | | 0.04 | 40.04 | 54.00 | 54.02 | 68.15 | 96.83 | 0.05 | 29.19 | 37.78 | 37.81 | 46.56 | 64.49 | | | | | | | 0.06 | 23.23 | 28.91 | 28.95 | 34.80 | 46.89 | 0.07 | 19.57 | 23.53 | 23.57 | 27.67 | 36.26 | 0.08 | 17.14 | 19.98 | 20.03 | 23.01 | 29.33 | 0.09 | 15.42 | 17.51 | 17.57 | 19.78 | 24.56 | 0.10 | 14.12 | 15.70 | 15.76 | 17.44 | 21.12 | | | | | | | 0.11 | 13.11 | 14.31 | 14.39 | 15.67 | 18.55 | 0.12 | 12.291 | 13.217 | 13.300 | 14.296 | 16.573 | 0.13 | 11.602 | 12.324 | 12.416 | 13.192 | 15.010 | 0.14 | 11.008 | 11.577 | 11.679 | 12.287 | 13.749 | 0.15 | 10.486 | 10.939 | 11.050 | 11.528 | 12.709 | | | | | | | 0.16 | 10.018 | 10.382 | 10.503 | 10.879 | 11.837 | 0.17 | 9.592 | 9.889 | 10.018 | 10.314 | 11.093 | 0.18 | 9.200 | 9.446 | 9.583 | 9.816 | 10.451 | 0.19 | 8.836 | 9.042 | 9.188 | 9.371 | 9.889 | 0.20 | 8.495 | 8.671 | 8.824 | 8.967 | 9.391 | | | | | | | 0.22 | 7.873 | 8.008 | 8.174 | 8.261 | 8.544 | 0.24 | 7.315 | 7.427 | 7.602 | 7.655 | 7.843 | 0.25 | 7.057 | 7.161 | 7.340 | 7.380 | 7.534 | 0.26 | 6.811 | 6.909 | 7.091 | 7.122 | 7.247 | 0.28 | 6.355 | 6.444 | 6.629 | 6.647 | 6.729 | 0.30 | 5.940 | 6.022 | 6.208 | 6.219 | 6.273 | | | | | | | 0.32 | 5.563 | 5.639 | 5.824 | 5.830 | 5.865 | 0.34 | 5.219 | 5.291 | 5.472 | 5.475 | 5.497 | 0.35 | 5.059 | 5.128 | 5.307 | 5.309 | 5.327 | 0.36 | 4.906 | 4.973 | 5.149 | 5.151 | 5.164 | 0.38 | 4.621 | 4.683 | 4.853 | 4.853 | 4.861 | 0.40 | 4.360 | 4.417 | 4.580 | 4.580 | 4.584 | | | | | | | 0.42 | 4.122 | 4.174 | 4.329 | 4.328 | 4.330 | 0.44 | 3.904 | 3.951 | 4.098 | 4.097 | 4.096 | 0.45 | 3.801 | 3.847 | 3.989 | 3.988 | 3.987 | 0.46 | 3.703 | 3.747 | 3.885 | 3.883 | 3.881 | 0.48 | 3.518 | 3.558 | 3.688 | 3.686 | 3.683 | 0.50 | 3.348 | 3.385 | 3.506 | 3.504 | 3.500 | | | | | | | 0.55 | 2.975 | 3.005 | 3.107 | 3.106 | 3.100 | 0.60 | 2.664 | 2.689 | 2.776 | 2.774 | 2.768 | 0.65 | 2.400 | 2.421 | 2.496 | 2.494 | 2.489 | 0.70 | 2.174 | 2.193 | 2.258 | 2.256 | 2.252 | 0.80 | 1.808 | 1.824 | 1.875 | 1.874 | 1.872 | 0.90 | 1.527 | 1.541 | 1.583 | 1.582 | 1.582 | 1.00 | 1.307 | 1.319 | 1.354 | 1.354 | 1.354 | | | | | | | 1.10 | 1.132 | 1.142 | 1.171 | 1.172 | 1.172 | 1.20 | 0.991 | 0.999 | 1.024 | 1.025 | 1.025 | 1.30 | 0.874 | 0.882 | 0.904 | 0.904 | 0.905 | 1.40 | 0.778 | 0.784 | 0.804 | 0.804 | 0.804 | 1.50 | 0.696 | 0.702 | 0.720 | 0.720 | 0.720 | | | | | | | 1.60 | 0.626 | 0.632 | 0.648 | 0.648 | 0.648 | 1.70 | 0.566 | 0.571 | 0.586 | 0.586 | 0.586 | 1.80 | 0.513 | 0.518 | 0.533 | 0.533 | 0.533 | 1.90 | 0.467 | 0.472 | 0.486 | 0.486 | 0.486 | 2.00 | 0.427 | 0.431 | 0.444 | 0.444 | 0.444 |
|
By the use of Poisson's equation relating the potential and charge-density distributions, it is possible to derive the Mott–Bethe formula for
in terms of the atomic scattering factors for X-rays,
:
where
is the permittivity of vacuum, or
[for λ in Å,
in Å, and
in electron units]. This was used for the other listed
values.
-
(a) Kinematical approximation. In the limiting case of a vanishingly weak interaction of the incident electrons with the scattering potential of the crystal, the Born series (4.3.1.5) may be terminated at the term , corresponding to single scattering. Then the diffracted wave is given for a potential as , with where R is the distance to the point of observation. For a periodic potential, , the scattering amplitude for the h beam is where the integral is taken over one unit cell and N is the number of unit cells. From (4.3.1.16) , it then follows that the scattering amplitude is proportional to the structure amplitude, ; The intensity of the h diffracted beam is then proportional to , and so to .
Similarly, we may write the differential scattering cross section for the scattering from a single isolated atom as ![[|\,f^B(s)|{}^2=K^2|V_i(s)|{}^2.\eqno (4.3.1.20)]](/teximages/cbch4o3/cbch4o3fd21.svg)
-
(b) Two-beam approximation. For some specific orientations of a crystal of relatively simple structure, the incident beam may be close to the Bragg angle for a strong, inner reflection but not for any other reflection. Then the approximation may be made that only those beams with indices 0 and h have appreciable intensity. The intensities of these beams for a parallel-sided, plate-shaped, centrosymmetric crystal are given in MacGillavry's (1940 ) development of the theory of Bethe (1928 ) as and , where is the incident-beam intensity, t is the crystal thickness, is the extinction distance given by , and is the excitation error which measures the distance of the reciprocal-lattice point h from the Ewald sphere.
A formula due to Blackman (1939 ), obtained by integrating (4.3.1.21) over , provides a useful first approximation for the intensities of ring or arc patterns given by polycrystalline material (see Section 2.5.2
).
-
(c) Phase-grating approximations. For extremely thin crystals, the scattering can be approximated by that of a two-dimensional potential distribution given by projection of the three-dimensional distribution in the beam direction. Then, by analogy with (4.3.1.6) , the emerging wave is when and the diffraction amplitudes are given by the Fourier transform of this expression.
For thicker crystals, this approximation applies in the limit of very high electron-accelerating voltage, with the value of σ appropriate for the Compton wavelength, λ = 0.024262 Å, viz σ = 0.0005068.
It may be noted that for the special case of a single layer of atoms the solution of the wave equations (4.3.1.2) or (4.3.1.4) , with the real potential (4.3.1.1) inserted, leads to a form equivalent to the Moliere high-energy approximation for the scattering by single atoms, namely where is a two-dimensional vector with components x, y, and and this, in the low-angle approximation, is the same as (4.3.1.23) . Then the scattered amplitude can be considered as made up from contributions from individual atoms that are equal (apart from bonding effects) to the complex atomic scattering amplitudes tabulated in connection with the diffraction of electrons by gases.
|
It has been shown by Fujiwara (1961
) that, at least for electron energies up to 1 MeV or so, the relativistic effects on diffraction amplitudes and geometry are adequately described by the use of relativisitically corrected values for the mass and wavelength of the electrons;
where
is the rest mass,
is the Compton wavelength
, and λ is given in Å if E is in volts. Consequently, σ varies with the incident electron energy as
, or
Values of λ,
β = ν/c, and σ are listed for various values of the accelerating voltage, E, in Table 4.3.2.1
with λ in Å and E in volts.
E (keV) | λ | 1/λ | | v/c | σ |
---|
1 | 0.387629 | 2.57979 | 1.00196 | 0.06247 | 0.0081126 | 2 | 0.273961 | 3.65016 | 1.00391 | 0.08821 | 0.0057448 | 3 | 0.223579 | 4.47270 | 1.00587 | 0.10788 | 0.0046975 | 4 | 0.193530 | 5.16715 | 1.00783 | 0.12439 | 0.0040741 | 5 | 0.173015 | 5.77986 | 1.00978 | 0.13887 | 0.0036493 | | | | | | | 6 | 0.157863 | 6.33460 | 1.01174 | 0.15191 | 0.0033361 | 7 | 0.146082 | 6.84548 | 1.01370 | 0.16384 | 0.0030931 | 8 | 0.136581 | 7.32168 | 1.01566 | 0.17490 | 0.0028975 | 9 | 0.128707 | 7.76958 | 1.01761 | 0.18524 | 0.0027358 | 10 | 0.122043 | 8.19383 | 1.01957 | 0.19498 | 0.0025991 | | | | | | | 15 | 0.099407 | 10.05963 | 1.02935 | 0.23711 | 0.0021374 | 20 | 0.085882 | 11.64383 | 1.03914 | 0.27186 | 0.0018641 | 25 | 0.076632 | 13.04940 | 1.04892 | 0.30184 | 0.0016790 | 30 | 0.069789 | 14.32899 | 1.05871 | 0.32837 | 0.0015433 | 35 | 0.064459 | 15.51381 | 1.06849 | 0.35227 | 0.0014386 | | | | | | | 40 | 0.060153 | 16.62414 | 1.07828 | 0.37406 | 0.0013548 | 45 | 0.056580 | 17.67403 | 1.08806 | 0.39410 | 0.0012859 | 50 | 0.053551 | 18.67366 | 1.09784 | 0.41268 | 0.0012280 | 55 | 0.050941 | 19.63072 | 1.10763 | 0.43000 | 0.0011786 | 60 | 0.048659 | 20.55115 | 1.11741 | 0.44622 | 0.0011357 | | | | | | | 65 | 0.046642 | 21.43968 | 1.12720 | 0.46147 | 0.0010982 | 70 | 0.044843 | 22.30012 | 1.13698 | 0.47586 | 0.0010650 | 75 | 0.043223 | 23.13560 | 1.14677 | 0.48948 | 0.0010354 | 80 | 0.041756 | 23.94874 | 1.15655 | 0.50239 | 0.0010087 | 85 | 0.040418 | 24.74173 | 1.16634 | 0.51467 | 0.0009847 | | | | | | | 90 | 0.039190 | 25.51646 | 1.17612 | 0.52637 | 0.0009628 | 95 | 0.038060 | 26.27454 | 1.18591 | 0.53754 | 0.0009428 | 100 | 0.037013 | 27.01738 | 1.19569 | 0.54822 | 0.0009244 | 120 | 0.033491 | 29.85866 | 1.23483 | 0.58667 | 0.0008638 | 140 | 0.030739 | 32.53222 | 1.27397 | 0.61956 | 0.0008180 | | | | | | | 160 | 0.028509 | 35.07642 | 1.31310 | 0.64810 | 0.0007820 | 180 | 0.026654 | 37.51759 | 1.35224 | 0.67314 | 0.0007529 | 200 | 0.025079 | 39.87466 | 1.39138 | 0.69531 | 0.0007289 | 250 | 0.021986 | 45.48412 | 1.48922 | 0.74101 | 0.0006839 | 300 | 0.019687 | 50.79517 | 1.58707 | 0.77652 | 0.0006526 | | | | | | | 350 | 0.017891 | 55.89295 | 1.68491 | 0.80483 | 0.0006297 | 400 | 0.016439 | 60.83109 | 1.78276 | 0.82786 | 0.0006122 | 450 | 0.015233 | 65.64563 | 1.88060 | 0.84691 | 0.0005984 | 500 | 0.014212 | 70.36195 | 1.97845 | 0.86286 | 0.0005873 | 550 | 0.013334 | 74.99858 | 2.07629 | 0.87638 | 0.0005783 | | | | | | | 600 | 0.012568 | 79.56945 | 2.17414 | 0.88794 | 0.0005707 | 650 | 0.011893 | 84.08529 | 2.27198 | 0.89793 | 0.0005644 | 700 | 0.011292 | 88.55452 | 2.36983 | 0.90661 | 0.0005590 | 750 | 0.010755 | 92.98385 | 2.46767 | 0.91421 | 0.0005543 | 800 | 0.010269 | 97.37874 | 2.56552 | 0.92091 | 0.0005503 | | | | | | | 850 | 0.009829 | 101.74364 | 2.66336 | 0.92684 | 0.0005468 | 900 | 0.009427 | 106.08226 | 2.76121 | 0.93212 | 0.0005437 | 950 | 0.009058 | 110.39769 | 2.85905 | 0.93684 | 0.0005410 | 1000 | 0.008719 | 114.69256 | 2.95690 | 0.94108 | 0.0005385 | 1100 | 0.008115 | 123.22919 | 3.15259 | 0.94836 | 0.0005344 | | | | | | | 1200 | 0.007593 | 131.70646 | 3.34828 | 0.95436 | 0.0005310 | 1300 | 0.007136 | 140.13516 | 3.54397 | 0.95936 | 0.0005282 | 1400 | 0.006733 | 148.52355 | 3.73966 | 0.96358 | 0.0005259 | 1500 | 0.006374 | 156.87810 | 3.93535 | 0.96718 | 0.0005240 |
|
Any scattering process, whether elastic or inelastic, which removes energy from the set of diffracted beams being considered, may be said to constitute an absorption process. For example, for a measurement of the intensities of the elastically scattered, sharp Bragg reflections from a crystal, any process which gives diffuse background scattering or results in a detectable loss of energy gives rise to absorption.
The diffracted amplitudes in such cases may be calculated, at least as a first approximation, in terms of a complex potential,
, containing an imaginary part
due to an `absorption function' and a small added real part
. Then under the crystallographic sign convention,
. Correspondingly, for a centrosymmetric crystal, the structure amplitude becomes complex and may be written
Under the appropriate conditions of observation, important contributions to the imaginary and real additions to the structure amplitudes may be given by the excitation of phonons, plasmons, or electron transitions, or by diffuse scattering due to crystal defects or disorder.
The additional terms
and
, however, are not invariant properties of the crystal structure but depend on the conditions of the diffraction experiment, such as the accelerating voltage and orientation of the incident beam, the aperture or resolution of the recording system, and the use of energy filtering or discrimination. In spite of this, it may often be convenient to treat them as being produced by phenomenological complex potentials, defined for a limited range of experimental conditions.
Tables 4.3.1.1
and 4.3.1.2
list values of
in Å for all neutral atoms and most chemically significant ions, respectively. The values have been given by Doyle & Turner (1968
) for several cases, denoted by RHF using the relativistic Hartree–Fock atomic potentials of Coulthard (1967
). For all other atoms and ions,
has been found using the Mott–Bethe formula [equation (4.3.1.15)
] for
, and the X-ray scattering factors of Table 2.2A of IT IV (1974
). Thus all other neutral atoms except hydrogen are based on the relativistic Hartree–Fock wavefunctions of Mann (1968
). These are designated by *RHF. For H and for ions below Rb, denoted by HF,
is ultimately based on the nonrelativistic Hartree–Fock wavefunctions of Mann (1968
). For ions above Rb, denoted by *DS, modified relativistic Dirac–Slater wavefunctions calculated by Cromer & Waber (1974
) are used.
For low values of s, the Mott formula becomes less accurate, since
tends to zero with s for neutral atoms. Except for the RHF atoms,
for s from 0.01 to 0.03 are omitted in Table 4.3.1.1
and for s from 0.04 to 0.11, only two decimal places are given.
is then accurate to the figure quoted. For these atoms,
was found using the formula given by Ibers (1958
):
where
is the mean-square atomic radius.
For ionized atoms,
. The values listed at s = 0 in Table 4.3.1.2
for RHF atoms were calculated by Doyle & Turner (1968
) with
in equation (4.3.1.13)
replaced by
, where
Here,
is the ionic charge. This approach omits the Coulomb field due to the excess or deficiency of charge on the nucleus. With the use of these values, the structure factor for forward scattering by a neutral unit cell containing ions may be found in the conventional way. Similar values are not available for other ions because the atomic potential data are lacking.
For computer applications, numerical approximations to the f(s) of these tables have been given by Doyle & Turner (1968
) as sums of Gaussians for the range s = 0 to 2 Å−1. An alternative is to make Gaussian fits to X-ray scattering factors, then use the Mott formula to derive electron scattering factors. As discussed by Peng & Cowley (1988
), this practice may lead to problems for small values of s. An additional problem occurs in high-resolution electron-microscopy (HREM) image-simulation programs, where it is usually necessary to have electron scattering factors for the range 0 to 6 Å−1. Fox, O'Keefe & Tabbernor (1989
) point out that extrapolation of the Gaussian fits of Doyle & Turner (1968
) to values past 2 Å−1 can be highly inaccurate. For the range of s from 2 to 6 Å−1, Fox et al. have used sums of polynomials to make accurate fits to the X-ray scattering factors of Doyle & Turner (1968
) for many elements (Section 6.1.1
), and electron scattering factors can be generated from these data by use of the Mott formula.
Recently, Rez, Rez & Grant (1994
) have published new tables of X-ray scattering factors obtained using a multiconfiguration Dirac–Fock code and two parameterizations in terms of four Gaussians, one of higher accuracy over the range of about 2 Å−1 and the other of lower accuracy over the extended range of about 6 Å−1. These authors suggest that electron scattering factors may best be obtained from these X-ray scattering factors by using the Mott formula. They provide a table of values for the electron scattering factor values for zero scattering angle,
, for many elements and ions, which may be of value for the calculation of mean inner potentials.
In order to calculate the Fourier coefficients V(h) of the potential distribution
, for insertion in the formulae used to calculate intensities [such as (4.3.1.6)
, (4.3.1.20)
, (4.3.1.21)
], or in the numerical methods for dynamical diffraction calculations, use
where
The
values are obtained from Tables 4.3.1.1
and 4.3.1.2
, and
is the unit-cell volume in Å3. The V(h) and the
tabulated are properties of the crystal structure and the isolated atoms, respectively, and are independent of the particular scattering theory assumed.
Expressions for the calculation of intensities in the kinematical approximation are given for powder patterns and oblique texture patterns in Section 2.5.4
, and for thin crystal plates in Section 2.5.2
of Volume B (IT B, 2001
). Since the formulas for kinematical scattering, such as (4.3.1.19)
and (4.3.1.20)
, include the parameter K = σ /λ, which varies with the energy of the electron beam through relativistic effects, it may be considered that the electron scattering factors for kinematical calculations should be multiplied by relativistic factors.
For high-energy electrons, the relativistic variations of the electron mass, the electron wavelength and the interaction constant, σ, become significant. The relations are
where
is the rest mass,
is the Compton wavelength,
, and
. Consequently,
varies with the incident electron energy as ![[\eqalignno{ \sigma &=2\pi /\{\lambda E[1+(1-\beta ^2){}^{1/2}]\} \cr &=2\pi e/hc\beta . & (4.3.1.34)}]](/teximages/cbch4o3/cbch4o3fd36.svg)
For the calculation of intensities in the kinematical approximation, the values of
listed in Tables 4.3.1.1 and 4.3.1.2, which were calculated using
, must be multiplied by
for electrons of velocity v. Values of λ, 1/λ,
, β = v/c, and σ are listed for various values of the accelerating voltage, E, in Table 4.3.2.1
.
The calculation of very large numbers of diffracted orders, i.e. more than 100 and often several thousand, requires the multislice procedure. This occurs because, for N diffracted orders, the multislice procedure involves the manipulation of arrays of size N, whereas the scattering matrix or the eigenvalue procedures involve manipulation of arrays of size N by N.
The simplest form of the multislice procedure presumes that the specimen is a parallel-sided plate. The surface normal is usually taken to be the z axis and the crystal structure axes are often chosen or transformed such that the c axis is parallel to z and the a and b axes are in the xy plane. This can often lead to rather unconventional choices for the unit-cell parameters. The maximum tilt of the incident beam from the surface normal is restricted to be of the order of 0.1 rad. For the calculation of wave amplitudes for larger tilts, the structure must be reprojected down an axis close to the incident-beam direction. For simple calculations, other crystal shapes are generally treated by the column approximation, that is the crystal is presumed to consist of columns parallel to the z axis, each column of different height and tilt in order to approximate the desired shape and variation of orientation.
The numerical procedure involves calculation of the transmission function through a thin slice, calculation of the vacuum propagation between centres of neighbouring slices, followed by evaluation in a computer of the iterated equation
in order to obtain the scattered wavefunction,
, emitted from slice n, i.e. for crystal thickness
; the symbol * indicates the operation `convolution' defined by
and
is the propagation function in the small-angle approximation between slice n − 1 and slice n over the slice spacing
. For simplicity, the equation is given for orthogonal axes and h′′, k′′ are the usually non-integral intercepts of the Laue circle on the reciprocal-space axes in units of (1/a), (1/b). The excitation errors,
, can be evaluated using
The transmission function for slice n is
where F denotes Fourier transformation from real to reciprocal space, and
and ![[\sigma={\pi\over W\lambda}\,{2\over{1+(1-\beta^2)^{1/2}}}]](/teximages/cbch4o3/cbch4o3fd140.svg)
where W is the beam voltage, v is the relativistic velocity of the electron, c is the velocity of light, and λ is the relativistic wavelength of the electron.
The operation * in (4.3.6.1)
is most effectively carried out for large N by the use of the convolution theorem of Fourier transformations. This efficiency presumes that there is available an efficient fast-Fourier-transform subroutine that is suitable for crystallographic computing, that is, that contains the usual crystallographic normalization factors and that can deal with a range of values for h, k that go from negative to positive. Then,
where F denotes
and
denotes
where
,
, and
are the sampling intervals in the unit cell. The array sizes used in the calculations of the Fourier transforms are commonly powers of 2 as is required by many fast Fourier subroutines. The array for
is usually defined over the central portion of the reserved computer array space in order to avoid oscillation in the Fourier transforms (Gibbs instability). It is usual to carry out a
beam calculation in an array of
, hence the critical timing interval in a multislice calculation is that interval taken by a fast Fourier transform for 4N coefficients. If the number of beams, N, is such that there is still appreciable intensity being scattered outside the calculation aperture, then it is usually necessary to impose a circular aperture on the calculation in order to prevent the symmetry of the calculation aperture imposing itself on the calculated wavefunction. This is most conveniently achieved by setting all p(h, k) coefficients outside the desired circular aperture to zero.
It is clear that the iterative procedure of (4.3.6.1)
means that care must be taken to avoid accumulation of error due to the precision of representation of numbers in the computer that is to be used. Practical experience indicates that a precision of nine significant figures (decimal) is more than adequate for most calculations. A precision of six to seven (decimal) figures (a common 32-bit floating-point representation) is only barely satisfactory. A computer that uses one of the common 64-bit representations (12 to 16 significant figures) is satisfactory even for the largest calculations currently contemplated.
The choice of slice thickness depends upon the maximum value of the projected potential within a slice and upon the validity of separation of the calculation into transmission function and propagation function. The second criterion is not severe and in practice sets an upper limit to slice thickness of about 10 Å. The first criterion depends upon the atomic number of atoms in the trial structure. In practice, the slice thickness will be too large if two atoms of medium to heavy atomic weight
are projected onto one another. It is not necessary to take slices less than one atomic diameter for calculations for fast electron (acceleration voltages greater than 50 keV) diffraction or microscopy. If the trial structure is such that the symmetry of the diffraction pattern is not strongly dependent upon the structure of the crystal parallel to the slice normal, then the slices may be all identical and there is no requirement to have a slice thickness related to the periodicity of the structure parallel to the surface normal. This is called the `no upper-layer-line' approximation. If the upper-layer lines are important, then the slice thickness will need to be a discrete fraction of the c axis, and the contents of each slice will need to reflect the actual atomic contents of each slice. Hence, if there were four slices per unit cell, then there would need to be four distinct q(h, k), each taken in the appropriate order as the multislice operation proceeds in thickness.
The multislice procedure has two checks that can be readily performed during a calculation. The first is applied to the transmission function, q(h, k), and involves the evaluation of a unitarity test by calculation of
for all h, k, where q* denotes the complex conjugate of q, and δ(h,k) is the Kronecker delta function. The second test can be applied to any calculation for which no phenomenological absorption potential has been used in the evaluation of the q(h, k). In that case, the sum of intensities of all beams at the final thickness should be no less than 0.9, the incident intensity being taken as 1.0. A value of this sum that is less than 0.9 indicates that the number of beams, N, has been insufficient. In some rare cases, the sum can be greater than 1.0; this is usually an indication that the number of beams has been allowed to come very close to the array size used in the convolution procedure. This last result does not occur if the convolution is carried out directly rather than by use of fast-Fourier-transform methods.
A more complete discussion of the multislice procedure can be obtained from Cowley (1975
) and Goodman & Moodie (1974
). These references are not exhaustive, but rather an indication of particularly useful articles for the novice in this subject.
Bloch waves, familiar in solid-state valence-band theory, arise as the basic wave solutions for a periodic structure. They are thus always implicit and often explicit in dynamical diffraction calculations, whether applied in perfect crystals, in almost perfect crystals with slowly varying defect strain fields or in more general structures that (see Subsection 4.3.6.1
) can always, for computations, be treated by periodic continuation.
The Schrödinger wave equation in a periodic structure,
can be applied to high-energy, relativistic electron diffraction, taking
as the relativistically corrected electron wave number (see Subsection 4.3.1.4
). The Fourier coefficients in the expression for the periodic potential are defined at reciprocal-lattice points g by the expression
where
is the Born scattering amplitude (see Subsection 4.3.1.2
) of the jth atom at position
in the unit cell of volume
and
is the Debye–Waller factor.
The simplest solution to (4.3.6.6)
is a single Bloch wave, consisting of a linear combination of plane-wave beams coupled by Bragg reflection.
In practice, only a limited number of terms N, corresponding to the most strongly excited Bragg beams, is included in (4.3.6.8)
. Substitution in (4.3.6.6)
then yields N simultaneous equations for the wave amplitudes ![[C_{\bf g}.]](/teximages/cbch4o3/cbch4o3fi1413.svg)
Usually, χ and the two tangential components
and
are fixed by matching to the incident wave at the crystal entrance surface.
then emerges as a root of the determinant of coefficients appearing in (4.3.6.9)
.
Numerical solution of (4.3.6.9)
is considerably simplified (Hirsch, Howie, Nicholson, Pashley & Whelan, 1977a
) in cases of transmission high-energy electron diffraction where all the important reciprocal-lattice points lie in the zero-order Laue zone
and
. The equations then reduce to a standard matrix eigenvalue problem (for which efficient subroutines are widely available):
where
and
is the distance, measured in the z direction, of the reciprocal-lattice point g from the Ewald sphere.
There will in general be N distinct eigenvalues
corresponding to N possible values
,
, each with its eigenfunction defined by N wave amplitudes
. The waves are normalized and orthogonal so that
In simple transmission geometry, the complete solution for the total coherent wavefunction
is
Inelastic and thermal-diffuse-scattering processes cause anomalous absorption effects whereby the amplitude of each component Bloch wave decays with depth z in the crystal from its initial value
. The decay constant is computed using an imaginary optical potential
with Fourier coefficients
(for further details of these see Humphreys & Hirsch, 1968
, and Subsection 4.3.1.5
and Section 4.3.2
).
The Bloch-wave, matrix-diagonalization method has been extended to include reciprocal-lattice points in higher-order Laue zones (Jones, Rackham & Steeds, 1977
) and, using pseudopotential scattering amplitudes, to the case of low-energy electrons (Pendry, 1974
).
The Bloch-wave picture may be compared with other variants of dynamical diffraction theory, which, like the multislice method (Subsection 4.3.6.1
), for example, employ plane waves whose amplitudes vary with position in real space and are determined by numerical integration of first-order coupled differential equations. For cases with
beams in perfect crystals or in crystals containing localized defects such as stacking faults or small point-defect clusters, the Bloch-wave method offers many advantages, particularly in thicker crystals with t > 1000 Å. For high-resolution image calculations in thin crystals where the periodic continuation process may lead to several hundred diffracted beams, the multislice method is more efficient. For cases of defects with extended strain fields or crystals illuminated at oblique incidence, coupled plane-wave integrations along columns in real space (Howie & Basinski, 1968
) can be the most efficient method.
The general advantage of the Bloch-wave method, however, is the picture it affords of wave propagation and scattering in both perfect and imperfect crystals. For this purpose, solutions of equations (4.3.6.9)
allow dispersion surfaces to be plotted in k space, covering with several sheets j all the wave points
for a given energy E. Thickness fringes and other interference effects then arise because of interference between waves excited at different points
. The average current flow at each point is normal to the dispersion surface and anomalous-absorption effects can be understood in terms of the distribution of Bloch-wave current within the unit cell. Detailed study of these effects, and the behaviour of dispersion surfaces as a function of energy, yields accurate data on scattering amplitudes via the critical-voltage effect (see Section 4.3.7
). Static crystal defects induce elastic scattering transitions
on sheets of the same dispersion surface. Transitions between points on dispersion surfaces of different energies occur because of thermal diffuse scattering, generation of electronic excitations or the emission of radiation by the fast electron. The Bloch-wave picture and the dispersion surface are central to any description of these phenomena. For further information and references, the reader may find it helpful to consult Section 5.2.10
of Volume B (IT B, 2001
).
J. Gjønnese and J. W. Steedsm
Current advances in quantitative electron diffraction are connected with improved experimental facilities, notably the combination of convergent-beam electron diffraction (CBED) with new detection systems. This is reflected in extended applications of electron diffraction intensities to problems in crystallography, ranging from valence-electron distributions in crystals with small unit cells to structure determination of biological molecules in membranes. The experimental procedures can be seen in relation to the two main principles for measurement of diffracted intensities from crystals:
-
– rocking curves, i.e. intensity profiles measured as function of deviation, sg, from the Bragg condition, and
-
– integrated intensities, which form the well known basis for X-ray and neutron diffraction determination of crystal structure.
|
Integrated intensities are not easily defined in the most common type of electron-diffraction pattern, viz the selected-area (SAD) spot pattern. This is due to the combination of dynamical scattering and the orientation and thickness variations usually present within the typically micrometre-size illuminated area. This combination leads to spot pattern intensities that are poorly defined averages over complicated scattering functions of many structure factors. Convergent-beam electron diffraction is a better alternative for intensity measurements, especially for inorganic structures with small-to-moderate unit cells. In CBED, a fine beam is focused within an area of a few hundred ångströms, with a divergence of the order of a tenth of a degree. The diffraction pattern then appears in the form of discs, which are essentially two-dimensional rocking curves from a small illuminated area, within which thickness and orientation can be regarded as constant. These intensity distributions are obtained under well defined conditions and are well suited for comparison with theoretical calculations. The intensity can be recorded either photographically, or with other parallel recording systems, viz YAG screen/CCD camera (Krivanek, Mooney, Fan, Leber & Meyer, 1991
) or image plates (Mori, Oikawa & Harada, 1990
) – or sequentially by a scanning system. The inelastic background can be removed by an energy filter (Krahl, Pätzold & Swoboda, 1990
; Krivanek, Gubbens, Dellby & Meyer, 1991
). Detailed intensity profiles in one or two dimensions can then be measured with high precision for low-order reflections from simple structures. But there are limitations also with the CBED technique: the crystal should be fairly perfect within the illuminated area and the unit cell relatively small, so that overlap between discs can be avoided. The current development of electron diffraction is therefore characterized by a wide range of techniques, which extend from the traditional spot pattern to two-dimensional, filtered rocking curves, adapted to the structure problems under study and the specimens that are available.
Spot-pattern
intensities are best for thin samples of crystals with light atoms, especially organic and biological materials. Dorset and co-workers (Dorset, Jap, Ho & Glaeser, 1979
; Dorset, 1991
) have shown how conventional crystallographic techniques (`direct phasing') can be applied in ab initio structure determination of thin organic crystals from spot intensities in projections. Two main complications were treated by them: bending of the crystal and dynamical scattering. Thin crystals will frequently be bent; this will give some integration of the reflection, but may also produce a slight distortion of the structure, as pointed out by Cowley (1961
), who proposed a correction formula. The thickness range for which a kinematical approach to intensities is valid was estimated theoretically by Dorset et al. (1979
). For organic crystals, they quoted a few hundred ångströms as a limit for kinematical scattering in dense projections at 100 kV.
Radiation damage is a problem, but with low-dose and cryo-techniques, electron-microscopy methods can be applied to many organic crystals, as shown by several recent investigations. Voigt-Martin, Yan, Gilmore, Shankland & Bricogne (1994
) collected electron-diffraction intensities from a beam-sensitive dione and constructed a 1.4 Å Fourier map by a direct method based on maximum entropy. Large numbers of electron-diffraction intensities have been collected from biological molecules crystallized in membranes. The structure amplitudes can be combined with phases extracted from high-resolution micrographs, following Henderson Unwin's (1975
) early work. Kühlbrandt, Wang & Fujiyoshi (1994
) collected about 18 000 amplitudes and 15 000 phases for a protein complex in an electron cryomicroscope operating at 4.2 K (Fujiyoshi et al., 1991
). Using these data, they determined the structure from a three-dimensional Fourier map calculated to 3.4 Å resolution. The assumption of kinematical scattering in such studies has been investigated by Spargo (1994
), who found the amplitudes to be kinematic within 4% but with somewhat larger deviations for phases.
For inorganic structures, spot-pattern intensities are less useful because of the stronger dynamical interactions, especially in dense zones. Nevertheless, it may be possible to derive a structure and refine parameters from spot-pattern intensities. Andersson (1975
) used experimental intensities from selected projections for comparison with dynamical calculations, including an empirical correction factor for orientation spread, in a structure determination of V14O8. Recently, Zou, Sukharev & Hovmöller (1993
) combined spot-pattern intensities read from film by the program ELD with image processing of high-resolution micrographs for structure determination of a complex perovskite.
A considerable improvement over the spot pattern has been obtained by the elegant double-precession technique devised by Vincent & Midgley (1994
). They programmed scanning coils above and below the specimen in the electron microscope so as to achieve simultaneous precession of the focused incident beam and the diffraction pattern around the optical axis. The net effect is equivalent to a precession of the specimen with a stationary incident beam. Integrated intensities can be obtained from reflections out to a Bragg angle
equal to the precession angle
for the zeroth Laue zone. In addition, reflections in the first and second Laue zones appear as broad concentric rings. Dynamical effects are reduced appreciably by this procedure, especially in the non-zero Laue zones. The experimental integrated intensities, Ig, must be multiplied with a geometrical factor analogous to the Lorentz factor in X-ray diffraction, viz
where nh is the reciprocal spacing between the zeroth and nth layers. The intensities can be used for structure determination by procedures taken over from X-ray crystallography, e.g. the conditional Patterson projections that are used by the Bristol group (Vincent, Bird & Steeds, 1984
). The precession method may be seen as intermediate between the spot pattern and the CBED technique. Another intermediate approach was proposed by Goodman (1976
) and used later by Olsen, Goodman & Whitfield (1985
) in the structure determination of a series of selenides. CBED patterns from thin crystals were taken in dense zones; intensities were measured at corresponding points in the discs, e.g. at the zone-axis position. Structure parameters were determined by fitting the observed intensities to dynamical calculations.
Higher precision and more direct comparisons with dynamical scattering calculations are achieved by measurements of intensity distributions within the CBED discs, i.e. one- or two-dimensional rocking curves. An up-to-date review of these techniques is found in the recent book by Spence & Zuo (1992
), where all aspects of the CBED technique, theory and applications are covered, including determination of lattice constants and strains, crystal symmetry, and fault vectors of defects. Refinement of structure factors in crystals with small unit cells are treated in detail. For determination of bond charges, the structure factors (Fourier potentials) should be determined to an accuracy of a few tenths of a percent; calculations must then be based on many-beam dynamical scattering theory, see Chapter 8.8
. Removal of the inelastic background by an energy filter will improve the data considerably; analytical expressions for the inelastic background including multiple-scattering contributions may be an alternative (Marthinsen, Holmestad & Høier, 1994
).
Early CBED applications to the determination of structure factors were based on features that can be related to dynamical effects in the two-beam case. Although insufficient for most accurate analyses, the two-beam expression for the intensity profile may be a useful guide. In its standard form,
where Ug and sg are Fourier potential and excitation error for the reflection g, k wave number and t thickness. The expression can be rewritten in terms of the eigenvalues γ(i, j) that correspond to the two Bloch-wave branches, i, j:
where
Note that the minimum separation between the branches i, j or the gap at the dispersion surface is
where
g is an extinction distance. The two-beam form is often found to be a good approximation to an intensity profile Ig(sg) even when other beams are excited, provided an effective potential
, which corresponds to the gap at the dispersion surface, is substituted for Ug. This is suggested by many features in CBED and Kikuchi patterns and borne out by detailed calculations, see e.g. Høier (1972
). Approximate expressions for
have been developed along different lines; the best known is the Bethe potential
Other perturbation approaches are based on scattering between Bloch waves, in analogy with the `interband scattering' introduced by Howie (1963
) for diffuse scattering; the term `Bloch-wave hybridization' was introduced by Buxton (1976
). Exact treatment of symmetrical few-beam cases is possible (see Fukuhara, 1966
; Kogiso & Takahashi, 1977
). The three-beam case (Kambe, 1957
; Gjønnes & Høier, 1971
) is described in detail in the book by Spence & Zuo (1992
).
Many intensity features can be related to the structure of the dispersion surface, as represented by the function γ(kx, ky). The gap [equation (4.3.7.4)
] is an important parameter, as in the four-beam symmetrical case in Fig. 4.3.7.1
. Intensity measurements along one dimension can then be referred to three groups, according to the width of the gap, viz:
-
small gap
– integrated intensity;
![[Figure 4.3.7.1]](/figures/Cbfig4o3o7o1thm.gif)
| Figure 4.3.7.1| top | pdf | (a) Dispersion-surface section for the symmetric four-beam case (0, g, g + h, m), γk is a function of kx, referred to (b), where kx = ky = 0 corresponds to the exact Bragg condition for all three reflections. The two gaps appear at sg = ±(Uh − Um)/k with widths (Ug ± Ug + h)/k. |
-
large gap
– rocking curve, thickness fringes;
-
zero gap
– critical effects.
|
A small gap
at the dispersion surface implies that the two-beam-like rocking curve above approaches a kinematical form and can be represented by an integrated intensity. Within a certain thickness range, this intensity may be proportional to
, with an angular width inversely proportional to gt. Several schemes have been proposed for measurement of relative integrated intensities for reflections in the outer, high-angle region, where the lines are narrow and can be easily separated from the background. Steeds (1984
) proposed use of the HOLZ (high-order Laue-zone) lines, which appear in CBED patterns taken with the central disc at the zone-axis position. Along a ring that defines the first-order Laue zone (FOLZ), reflections appear as segments that can be associated with scattering from strongly excited Bloch waves in the central ZOLZ part into the FOLZ reflections. Vincent, Bird & Steeds (1984
) proposed an intensity expression
for integrated intensity for a line segment associated with scattering from (or into) the ZOLZ Bloch wave j.
is here the excitation coefficient and β(j) the matrix element for scattering between the Bloch wave j and the plane wave g. μ(j) and μ are absorption coefficients for the Bloch wave and plane wave, respectively; t is the thickness. From measurements of a number of such FOLZ (or SOLZ) reflections, they were able to carry out ab initio structure determinations using so-called conditional Patterson projections and coordinate refinement. Tanaka & Tsuda (1990
) have refined atomic positions from zone-axis HOLZ intensities. Ratios between HOLZ intensities have been used for determination of the Debye–Waller factor (Holmestad, Weickenmeier, Zuo, Spence & Horita, 1993
).
Another CBED approach to integrated intensities is due to Taftø & Metzger (1985
). They measured a set of high-order reflections along a systematic row with a wide-aperture CBED tilted off symmetrical incidence. A number of high-order reflections are then simultaneously excited in a range where the reflections are narrow and do not overlap. Gjønnes & Bøe (1994
) and Ma, Rømming, Lebech & Gjønnes (1992
) applied the technique to the refinement of coordinates and thermal parameters in high-Tc superconductors and intermetallic compounds. The validity and limitation of the kinematical approximation and dynamic potentials in this case has been discussed by Gjønnes & Bøe (1994
).
Zero gap
at the dispersion surface corresponds to zero effective Fourier potential or, to be more exact, an accidental degeneracy, γ(i) = γ(j), in the Bloch-wave solution. This is the basis for the critical-voltage method first shown by Watanabe, Uyeda & Fukuhara (1969
). From vanishing contrast of the Kikuchi line corresponding to a second-order reflection 2g, they determined a relation between the structure factors Ug and U2g. Gjønnes & Høier (1971
) derived the condition for the accidental degeneracy in the general centrosymmetrical three-beam case 0,g,h, expressed in terms of the excitation errors sg,h and Fourier potentials Ug,h,g−h, viz
where m and m0 are the relativistic and rest mass of the incident electron. Experimentally, this condition is obtained at a particular voltage and diffraction condition as vanishing line contrast of a Kikuchi or Kossel line – or as a reversal of a contrast feature. The second-order critical-voltage effect is then obtained as a special case, e.g. by the mass ratio:
Measurements have been carried out for a number of elements and alloy phases; see the review by Fox & Fisher (1988
) and later work on alloys by Fox & Tabbernor (1991
). Zone-axis critical voltages have been used by Matsuhata & Steeds (1987
). For analytical expressions and experimental determination of non-systematic critical voltages, see Matsuhata & Gjønnes (1994
).
Large gaps
at the dispersion surface are associated with strong inner reflections – and a strong dynamical effect of two-beam-like character. The absolute magnitude of the gap – or its inverse, the extinction distance – can be obtained in different ways. Early measurements were based on the split of diffraction spots from a wedge, see Lehmpfuhl (1974
), or the corresponding fringe periods measured in bright- and dark-field micrographs (Ando, Ichimiya & Uyeda, 1974
). The most precise and applicable large-gap methods are based on the refinement of the fringe pattern in CBED discs from strong reflections, as developed by Goodman & Lehmpfuhl (1967
) and Voss, Lehmpfuhl & Smith (1980
). In recent years, this technique has been developed to high perfection by means of filtered CBED patterns, see Spence & Zuo (1992
) and papers referred to therein. See also Chapter 8.8
.
The gap at the dispersion surface can also be obtained directly from the split observed at the crossing of a weak Kikuchi line with a strong band. Gjønnes & Høier (1971
) showed how this can be used to determine strong low-order reflections. High voltage may improve the accuracy (Terasaki, Watanabe & Gjønnes, 1979
). The sensitivity of the intersecting Kikuchi-line (IKL) method was further increased by the use of CBED instead of Kikuchi patterns (Matsuhata, Tomokiyo, Watanabe & Eguchi, 1984
; Taftø & Gjønnes, 1985
). In a recent development, Høier, Bakken, Marthinsen & Holmestad (1993
) have measured the intensity distribution in the CBED discs around such intersections and have refined the main structure factors involved.
Two-dimensional rocking curves
collected by CBED patterns around the axis of a dense zone are complicated by extensive many-beam dynamical interactions. The Bristol–Bath group (Saunders, Bird, Midgley & Vincent, 1994
) claim that the strong dynamic effects can be exploited to yield high sensitivity in refinement of low-order structure factors. They have also developed procedures for ab initio structure determination based on zone-axis patterns (Bird & Saunders, 1992
), see Chapter 8.8
.
Determination of phase invariants.
It has been known for some time (e.g. Kambe, 1957
) that the dynamical three-beam case contains information about phase. As in the X-ray case, measurement of dynamical effects can be used to determine the value of triplets (Zuo, Høier & Spence, 1989
) and to determine phase angles to better than one tenth of a degree (Zuo, Spence, Downs & Mayer, 1993
) which is far better than any X-ray method. Bird (1990
) has pointed out that the phase of the absorption potential may differ from the phase of the real potential.
Thickness
is an important parameter in electron-diffraction experiments. In structure-factor determination based on CBED patterns, thickness is often included in the refinement. Thickness can also be determined directly from profiles connected with large gaps at the dispersion surface (Goodman & Lehmpfuhl, 1967
; Blake, Jostsons, Kelly & Napier, 1978
; Glazer, Ramesh, Hilton, & Sarikaya, 1985
). The method is based on the outer part of the fringe profile, which is not so sensitive to the structure factor. The intensity minimum of the ith fringe in the diffracted disc occurs at a position corresponding to the excitation error si and expressed as
where ni is a small integer describing the order of the minimum. This equation can be arranged in two ways for graphic determination of thickness. The commonest method appears to be to plot (si/ni)2 against 1/ni2and then determine the thickness from the intersection with the ordinate axis (Kelly, Jostsons, Blake & Napier, 1975
). Glazer et al. (1985
) claim that the method originally proposed by Ackermann (1948
), where
is plotted against ni and the thickness is taken from the slope, is more accurate. In both cases, the outer part of the rocking curve is emphasized; exact knowledge of the gap is not necessary for a good determination of thickness, provided the assumption of a two-beam-like rocking curve is valid.
J. C. H. Spencel and J. M. Cowleyb‡
For the crystallographic study of real materials, high-resolution electron microscopy (HREM) can provide a great deal of information that is complementary to that obtainable by X-ray and neutron diffraction methods. In contrast to the statistically averaged information that these other methods provide, the great power of HREM lies in its ability to elucidate the detailed atomic arrangements of individual defects and the microcrystalline structure in real crystals. The defects and inhomogeneities of real crystals frequently exert a controlling influence on phase-transition mechanisms and more generally on all the electrical, mechanical, and thermal properties of solids. The real-space images that HREM provides (such as that shown in Fig. 4.3.8.1
) can give an immediate and dramatic impression of chemical crystallography processes, unobtainable by other methods. Their atomic structure is of the utmost importance for an understanding of the properties of real materials. The HREM method has proven powerful for the determination of the structure of such defects and of the submicrometre-sized microcrystals that constitute many polyphase materials.
![[Figure 4.3.8.1]](/figures/Cbfig4o3o8o1thm.gif)
| Figure 4.3.8.1| top | pdf | Atomic resolution image of a tantalum-doped tungsten trioxide crystal (pseudo-cubic structure) showing extended crystallographic shear-plane defects (C), pentagonal-column hexagonal-tunnel (PCHT) defects (T), and metallization of the surface due to oxygen desorption (JEOL 4000EX, crystal thickness less than 200 Å, 400 kV, Cs = 1 mm). Atomic columns are black. [Smith, Bursill & Wood (1985 ).] |
In summary, HREM should be considered the technique of choice where a knowledge of microcrystal size, shape or morphology is required. In addition, it can be used to reveal the presence of line and planar defects, inclusions, grain boundaries and phase boundaries, and, in favourable cases, to determine atomic structure. Surface atomic structure and reconstruction have also been studied by HREM. However, meaningful results in this field require accurately controlled ultra-high-vacuum conditions. The determination of the atomic structure of point defects by HREM so far has proven extremely difficult, but this situation is likely to change in the near future.
The following sections are not intended to review the applications of HREM, but rather to provide a summary of the main theoretical results of proven usefulness in the field, a selected bibliography, and recommendations for good experimental practice. At the time of writing (1997), the point resolution of HREM machines lies between 1 and 2 Å.
The function of the objective lens in an electron microscope is to perform a Fourier synthesis of the Bragg-diffracted electron beams scattered (in transmission) by a thin crystal, in order to produce a real-space electron image in the plane r. This electron image intensity can be written
where
represents the complex amplitude of the diffracted wave after diffraction in the crystal as a function of the reciprocal-lattice vector u [magnitude
in the plane perpendicular to the beam, so that the wavevector of an incident plane wave is written
. Following the convention of Section 2.5.2
in IT B (2001
), we write
. The function χ(u) is the phase factor for the objective-lens transfer function and P(u) describes the effect of the objective aperture: ![[P({\bf u}) =\cases{1 \quad\hbox{for }|{\bf u}|\lt u_0 \cr0 \quad\hbox{for }|{\bf u}|\ge u_0.}]](/teximages/cbch4o3/cbch4o3fd165.svg)
For a periodic object, the image wavefunction is given by summing the contributions from the set of reciprocal-lattice points, g, so that
For atomic resolution, with
1 Å−1, it is apparent that, for all but the simplest structures and smallest unit cells, this synthesis will involve many hundreds of Bragg beams. A scattering calculation must involve an even larger number of beams than those that contribute resolvable detail to the image, since, as described in Section 2.5.2
in IT B (2001
), all beams interact strongly through multiple coherent scattering. The theoretical basis for HREM image interpretation is therefore the dynamical theory of electron diffraction in the transmission (or Laue) geometry [see Chapter 5.2
in IT B (2001
)]. The resolution of HREM images is limited by the aberrations of the objective electron lens (notably spherical aberration) and by electronic instabilities. An intuitive understanding of the complicated effect of these factors on image formation from multiply scattered Bragg beams is generally not possible. To provide a basis for understanding, therefore, the following section treats the simplified case of few-beam `lattice-fringe' images, in order to expose the relationship between the crystal potential, its structure factors, electron-lens aberrations, and the electron image.
Image formation in the transmission electron microscope is conventionally treated by analogy with the Abbe theory of coherent optical imaging. The overall process is subdivided as follows. (a) The problem of beam–specimen interaction for a collimated kilovolt electron beam traversing a thin parallel-sided slab of crystal in a given orientation. The solution to this problem gives the elastically scattered dynamical electron wavefunction
, where r is a two-dimensional vector lying in the downstream surface of the slab. Computer algorithms for dynamical scattering are described in Section 4.3.6
. (b) The effects of the objective lens are incorporated by multiplying the Fourier transform of
by a function T(u), which describes both the wavefront aberration of the lens and the diffraction-limiting effects of any apertures. The dominant aberrations are spherical aberration, astigmatism, and defect of focus. The image intensity is then formed from the modulus squared of the Fourier transform of this product. (c) All partial coherence effects may be incorporated by repeating this procedure for each of the component energies and directions that make up the illumination from an extended electron source, and summing the resulting intensities. Because this procedure requires a separate dynamical calculation for each component direction of the incident beam, a number of useful approximations of restricted validity have been developed; these are described in Subsection 4.3.8.4
. This treatment of partial coherence assumes that a perfectly incoherent effective source can be identified. For field-emission HREM instruments, a coherent sum (over directions) of complex image wavefunctions may be required.
General treatments of the subject of HREM can be found in the texts by Cowley (1981
) and Spence (1988b
). The sign conventions used throughout the following are consistent with the standard crystallographic convention of Section 2.5.2
of IT B (2001
), which assumes a plane wave of form
and so is consistent with X-ray usage.
We consider few-beam lattice images, in order to understand the effects of instrumental factors on electron images, and to expose the conditions under which they faithfully represent the scattering object. The case of two-beam lattice images is instructive and contains, in simplified form, most of the features seen in more complicated many-beam images. These fringes were first observed by Menter (1956
) and further studied in the pioneering work of Komoda (1964
) and others [see Spence (1988b
) for references to early work]. The electron-microscope optic-axis orientation, the electron beam, and the crystal setting are indicated in Fig. 4.3.8.2
. If an objective aperture is used that excludes all but the two beams shown from contributing to the image, equation (4.3.8.2)
gives the image intensity along direction g for a centrosymmetric crystal of thickness t as ![[\eqalignno{ I(x,t) &=|\Psi_0(t)|^2+|\Psi_{\bf g}(t)|^2 \cr &\quad +2|\Psi_0||\Psi_{\bf g}|\cos\{2\pi x/d_{\bf g}+\chi(u_{\bf g})\eta_{\bf g}(t)-\eta_0(t)\}. & (4.3.8.3)}]](/teximages/cbch4o3/cbch4o3fd167.svg)
![[Figure 4.3.8.2]](/figures/Cbfig4o3o8o2thm.gif)
| Figure 4.3.8.2| top | pdf | Imaging conditions for few-beam lattice images. For three-beam axial imaging shown in (c), the formation of half-period fringes is also shown. |
The Bragg-diffracted beams have complex amplitudes
. The lattice-plane period is
in direction g [Miller indices (hkl)]. The lens-aberration phase function, including only the effects of defocus Δf and spherical aberration (coefficient
), is given by
The effects of astigmatism and higher-order aberrations have been ignored. The defocus, Δf, is negative for the objective lens weakened (i.e. the focal length increased, giving a bright first Fresnel-edge fringe). The magnitude of the reciprocal-lattice vector
, where
is the Bragg angle. If these two Bragg beams were the only beams excited in the crystal (a poor approximation for quantitative work), their amplitudes would be given by the `two-beam' dynamical theory of electron diffraction as
where
is the two-beam extinction distance,
is a Fourier coefficient of crystal potential,
is the excitation error (see Fig. 4.3.8.2
),
, and the interaction parameter σ is defined in Section 2.5.2
of IT B (2001
).
The two-beam image intensity given by equation (4.3.8.3)
therefore depends on the parameters of crystal thickness (t), orientation
, structure factor
, objective-lens defocus Δf, and spherical-aberration constant
. We consider first the variation of lattice fringes with crystal thickness in the two-beam approximation (Cowley, 1959
; Hashimoto, Mannami & Naiki, 1961
). At the exact Bragg condition
, equations (4.3.8.5)
and (4.3.8.3)
give
If we consider a wedge-shaped crystal with the electron beam approximately normal to the wedge surface and edge, and take x and g parallel to the edge, this equation shows that sinusoidal lattice fringes are expected whose contrast falls to zero (and reverses sign) at thicknesses of
. This apparent abrupt translation of fringes (by d/2 in the direction x) at particular thicknesses is also seen in some experimental many-beam images. The effect of changes in focus (due perhaps to variations in lens current) is seen to result in a translation of the fringes (in direction x), while time-dependent variations in the accelerating voltage have a similar effect. Hence, time-dependent variations of the lens focal length or the accelerating voltage result in reduced image contrast (see below). If the illumination makes a small angle
with the optic axis, the intensity becomes
For a uniformly intense line source subtending a semiangle
, the total lattice-fringe intensity is
The resulting fringe visibility
is proportional to
, where
. The contrast falls to zero for β = π, so that the range of focus over which fringes are expected is
. This is the approximate depth of field for lattice images due to the effects of the finite source size alone.
The case of three-beam fringes in the axial orientation is of more practical importance [see Fig. 4.3.8.2(b)
]. The image intensity for
and
is
The lattice image is seen to consist of a constant background plus cosine fringes with the lattice spacing, together with cosine fringes of half this spacing. The contribution of the half-spacing fringes is independent of instrumental parameters (and therefore of electronic instabilities if
). These fringes constitute an important HREM image artifact. For kinematic scattering,
and only the half-period fringes will then be seen if
, or for focus settings
Fig. 4.3.8.2(c)
indicates the form of the fringes expected for two focus settings with differing half-period contributions. As in the case of two-beam fringes, dynamical scattering may cause
to be severely attenuated at certain thicknesses, resulting also in a strong half-period contribution to the image.
Changes of 2π in
in equation (4.3.8.7)
leave I(x, t) unchanged. Thus, changes of defocus by amounts
or changes in
by
yield identical images. The images are thus periodic in both Δf and
. This is a restricted example of the more general phenomenon of n-beam Fourier imaging discussed in Subsection 4.3.8.3
.
We note that only a single Fourier period will be seen if
is less than the depth of field Δz. This leads to the approximate condition
, which, when combined with the Bragg law, indicates that a single period only of images will be seen when adjacent diffraction discs just overlap.
The axial three-beam fringes will coincide with the lattice planes, and show atom positions as dark if
and
. This total phase shift of −π between
and the scattered beams is the desirable imaging condition for phase contrast, giving rise to dark atom positions on a bright background. This requires
as a condition for identical axial three-beam lattice images for
. This family of lines has been plotted in Fig. 4.3.8.3
for the (111) planes of silicon. Dashed lines denote the locus of `white-atom' images (reversed contrast fringes), while the dotted lines indicate half-period images. In practice, the depth of field is limited by the finite illumination aperture
, and few-beam lattice-image contrast will be a maximum at the stationary-phase focus setting, given by ![[\Delta f_0=-C_s\lambda^2u^2_{\bf g}. \eqno (4.3.8.11)]](/teximages/cbch4o3/cbch4o3fd178.svg)
![[Figure 4.3.8.3]](/figures/Cbfig4o3o8o3thm.gif)
| Figure 4.3.8.3| top | pdf | A summary of three- (or five-) beam axial imaging conditions. Here, Δff is the Fourier image period, Δ f0 the stationary-phase focus, Cs(0) the image period in Cs, and a scattering phase of −π/2 is assumed. The lines are drawn for the (111) planes of silicon at 100 kV with θc = 1.4 mrad. |
This choice of focus ensures
for
, and thus ensures the most favourable trade-off between increasing
and loss of fringe contrast for lattice planes g. Note that
is not equal to the Scherzer focus
(see below). This focus setting is also indicated on Fig. 4.3.8.3
, and indicates the instrumental conditions which produce the most intense (111) three- (or five-) beam axial fringes in silicon. For three-beam axial fringes of spacing d, it can be shown that the depth of field
is approximately
This depth of field, within which strong fringes will be seen, is indicated as a boundary on Fig. 4.3.8.3
. Thus, the finer the image detail, the smaller is the focal range over which it may be observed, for a given illumination aperture
.
Fig. 4.3.8.4
shows an exact dynamical calculation for the contrast of three-beam axial fringes as a function of Δf in the neighbourhood of
. Both reversed contrast and half-period fringes are noted. The effects of electronic instabilities on lattice images are discussed in Subsection 4.3.8.3
. It is assumed above that
is sufficiently small to allow the neglect of any changes in diffraction conditions (Ewald-sphere orientation) within
. Under a similar approximation but without the approximations of transfer theory, Desseaux, Renault & Bourret (1977
) have analysed the effect of beam divergence on two-dimensional five-beam axial lattice fringes.
![[Figure 4.3.8.4]](/figures/Cbfig4o3o8o4thm.gif)
| Figure 4.3.8.4| top | pdf | The contrast of few-beam lattice images as a function of focus in the neighbourhood of the stationary-phase focus [see Olsen & Spence (1981 )]. |
When two-dimensional patterns of fringes are considered, the Fourier imaging conditions become more complex (see Subsection 4.3.8.3
), but half-period fringe systems and reversed-contrast images are still seen. For example, in a cubic projection, a focus change of
results in an image shifted by half a unit cell along the cell diagonal. It is readily shown that
if
when n, m are integers and a and b are the two dimensions of any orthogonal unit cell that can be chosen for
. Thus, changes in focus by
produce identical images in crystals for which such a cell can be chosen, regardless of the number of beams contributing (Cowley & Moodie, 1960
).
For closed-form expressions for the few-beam (up to 10 beams) two-dimensional dynamical Bragg-beam amplitudes
in orientations of high symmetry, the reader is referred to the work of Fukuhara (1966
).
We define a crystal structure image as a high-resolution electron micrograph that faithfully represents a projection of a crystal structure to some limited resolution, and which was obtained using instrumental conditions that are independent of the structure, and so require no a priori knowledge of the structure. The resolution of these images is discussed in Subsection 4.3.8.6
, and their variation with instrumental parameters in Subsection 4.3.8.4
.
Equation (4.3.8.2)
must now be modified to take account of the finite electron source size used and of the effects of the range of energies present in the electron beam. For a perfect crystal we may write, as in equation (2.5.2.36)
in IT B (2001
),
for the total image intensity due to an electron source whose normalized distribution of wavevectors is
, where
has components
, and which extends over a range of energies corresponding to the distribution of focus
. If χ is also assumed to vary linearly across
and changes in the diffraction conditions over this range are assumed to make only negligible changes in the diffracted-beam amplitude
, the expression for a Fourier coefficient of the total image intensity
becomes
where γ(h) and β(g) are the Fourier transforms of
and
, respectively.
For the imaging of very thin crystals, and particularly for the case of defects in crystals, which are frequently the objects of particular interest, we give here some useful approximations for HREM structure images in terms of the continuous projected crystal potential
where the projection is taken in the electron-beam direction. A brief summary of the use of these approximations is included in Section 2.5.2
of IT B (2001
) and computing methods are discussed in Subsection 4.3.8.5
and Section 4.3.4
.
The projected-charge-density (PCD) approximation (Cowley & Moodie, 1960
) gives the HREM image intensity (for the simplified case where
) as
where
is the projected charge density for the specimen (including the nuclear contribution) and is related to
through Poisson's equation. Here,
is the specimen dielectric constant. This approximation, unlike the weak-phase-object approximation (WPO), includes multiple scattering to all orders of the Born series, within the approximation that the component of the scattering vector is zero in the beam direction (a `flat' Ewald sphere). Contrast is found to be proportional to defocus and to
. The failure conditions of this approximation are discussed by Lynch, Moodie & O'Keefe (1975
); briefly, it fails for
(and hence if
, Δf or
becomes large) or for large thicknesses t (t
7 nm is suggested for specimens of medium atomic weight and λ = 0.037 Å). The PCD result becomes increasingly accurate with increasing accelerating voltage for small
.
The WPO approximation has been used extensively in combination with the Scherzer-focus condition (Scherzer, 1949
) for the interpretation of structure images (Cowley & Iijima, 1972
). This approximation neglects multiple scattering of the beam electron and thereby allows the application of the methods of linear transfer theory from optics. The image intensity is then given, for plane-wave illumination, by
where
denotes Fourier transform, * denotes convolution, and u and v are orthogonal components of the two-dimensional scattering vector u. The function S(x, y) is sharply peaked and negative at the `Scherzer focus'
and the optimum objective aperture size
It forms the impulse response of an electron microscope for phase contrast. Contrast is found to be proportional to
and to the interaction parameter σ, which increases very slowly with accelerating voltage above about 500 keV. The point resolution [see Subsection 2.5.2.9
of IT B (2001
) and Subsection 4.3.8.6
] is conventionally defined from equation (4.3.8.15b) as
, or ![[d_p=0.66 \, C^{1/4}_s \lambda^{3/4}. \eqno (4.3.8.16)]](/teximages/cbch4o3/cbch4o3fd188.svg)
The occurrence of appreciable multiple scattering, and therefore of the failure of the WPO approximation, depends on specimen thickness, orientation, and accelerating voltage. Detailed comparisons between accurate multiple-scattering calculations, the PCD approximation, and the WPO approximation can be found in Lynch, Moodie & O'Keefe (1975
) and Jap & Glaeser (1978
). As a very rough guide, equation (4.3.8.14)
can be expected to fail for light elements at 100 keV and thicknesses greater than about 5.0 nm. Multiple-scattering effects have been predicted within single atoms of gold at 100 keV.
The WPO approximation may be extended to include the effects of an extended source (partial spatial coherence) and a range of incident electron-beam energies (temporal coherence). General methods for incorporating these effects in the presence of multiple scattering are described in Subsection 4.3.8.5
. Under the approximations of linear imaging outlined below, it can be shown (Wade & Frank, 1977
; Fejes, 1977
) that
in equation (4.3.8.14)
may be replaced by
if astigmatism is absent. Here,
and
. In addition,
is the Fourier transform of the source intensity distribution (assumed Gaussian), so that
is small in regions where the slope of
is large, resulting in severe attenuation of these spatial frequencies. If the illuminating beam divergence
is chosen as the angular half width for which the distribution of source intensity falls to half its maximum value, then
The quantity q is defined by
where T2 expresses a coupling between the effects of partial spatial coherence and temporal coherence. This term can frequently be neglected under HREM conditions [see Wade & Frank (1977
) for details]. The damping envelope due to chromatic effects is described by the parameter
where
and
are the variances in the statistically independent fluctuations of accelerating voltage
and objective-lens current
. The r.m.s. value of the high voltage fluctuation is equal to the standard deviation
. The full width at half-maximum height of the energy distribution of electrons leaving the filament is
Here,
is the chromatic aberration constant of the objective lens.
Equations (4.3.8.14)
and (4.3.8.17)
indicate that under linear imaging conditions the transfer function for HREM contains a chromatic damping envelope more severely attenuating than a Gaussian of width
which is present in the absence of any objective aperture P(u). The resulting resolution limit
is known as the information resolution limit (see Subsection 4.3.8.6
) and depends on electronic instabilities and the thermal-energy spread of electrons leaving the filament. The reduction in the contribution of particular diffracted beams to the image due to limited spatial coherence is minimized over those extended regions for which
is small, called passbands, which occur when
The Scherzer focus
corresponds to n = 0. These passbands become narrower and move to higher u values with increasing n, but are subject also to chromatic damping effects. The passbands occur between spatial frequencies
and
, where
Their use for extracting information beyond the point resolution of an electron microscope is further discussed in Subsection 4.3.8.6
.
Fig. 4.3.8.5
shows transfer functions for a modern instrument for n = 0 and 1. Equations (4.3.8.14)
and (4.3.8.17)
provide a simple, useful, and popular approach to the interpretation of HREM images and valuable insights into resolution-limiting factors. However, it must be emphasized that these results apply only (amongst other conditions) for
(in crystals) and therefore do not apply to the usual case of strong multiple electron scattering. Equation (4.3.8.13b)
does not make this approximation. In real space, for crystals, the alignment of columns of atoms in the beam direction rapidly leads to phase changes in the electron wavefunction that exceed π/2, leading to the failure of equation (4.3.8.14)
. Accurate quantitative comparisons of experimental and simulated HREM images must be based on equation (4.3.8.13a)
, or possibly (4.3.8.13b)
, with
obtained from many-beam dynamical calculations of the type described in Subsection 4.3.8.5
.
![[Figure 4.3.8.5]](/figures/Cbfig4o3o8o5thm.gif)
| Figure 4.3.8.5| top | pdf | (a) The transfer function for a 400 kV electron microscope with a point resolution of 1.7 Å at the Scherzer focus; the curve is based on equation (4.3.8.17) . In (b) is shown a transfer function for similar conditions at the first `passband' focus [n = 1 in equation (4.3.8.22) ]. |
For the structure imaging of specific types of defects and materials, the following references are relevant. (i) For line defects viewed parallel to the line, d'Anterroches & Bourret (1984
); viewed normal to the line, Alexander, Spence, Shindo, Gottschalk & Long (1986
). (ii) For problems of variable lattice spacing (e.g. spinodal decomposition), Cockayne & Gronsky (1981
). (iii) For point defects and their ordering, in tunnel structures, Yagi & Cowley (1978
); in semiconductors, Zakharov, Pasemann & Rozhanski (1982
); in metals, Fields & Cowley (1978
). (iv) For interfaces, see the proceedings reported in Ultramicroscopy (1992), Vol. 40, No. 3. (v) For metals, Lovey, Coene, Van Dyck, Van Tendeloo, Van Landuyt & Amelinckx (1984
). (vi) For organic crystals, Kobayashi, Fujiyoshi & Uyeda (1982
). (vii) For a general review of applications in solid-state chemistry, see the collection of papers reported in Ultramicroscopy (1985), Vol. 18, Nos. 1–4. (viii) Radiation-damage effects are observed at atomic resolution by Horiuchi (1982
).
The instrumental parameters that affect HREM images include accelerating voltage, astigmatism, optic-axis alignment, focus setting Δf, spherical-aberration constant
, beam divergence
, and chromatic aberration constant
. Crystal parameters influencing HREM images include thickness, absorption, ionicity, and the alignment of the crystal zone axis with the beam, in addition to the structure factors and atom positions of the sample. The accurate measurement of electron wavelength or accelerating voltage has been discussed by many workers, including Uyeda, Hoier and others [see Fitzgerald & Johnson (1984
) for references]. The measurement of Kikuchi-line spacings from crystals of known structure appears to be the most accurate and convenient method for HREM work, and allows an overall accuracy of better than 0.2% in accelerating voltage. Fluctuations in accelerating voltage contribute to the chromatic damping term Δ in equation (4.3.8.19)
through the variance
. With the trend toward the use of higher accelerating voltages for HREM work, this term has become especially significant for the consideration of the information resolution limit [equation (4.3.8.21)
].
Techniques for the accurate measurement of astigmatism and chromatic aberration are described by Spence (1988b
). The displacement of images of small crystals with beam tilt may be used to measure
; alternatively, the curvature of higher-order Laue-zone lines in CBED patterns has been used. The method of Budinger & Glaeser (1976
) uses a similar dark-field image-displacement method to provide values for both Δf and
, and appears to be the most convenient and accurate for HREM work. The analysis of optical diffractograms initiated by Thon and co-workers from HREM images of thin amorphous films provides an invaluable diagnostic aid for HREM work; however, the determination of
by this method is prone to large errors, especially at small defocus. Diffractograms provide a rapid method for the determination of focus setting (see Krivanek, 1976
) and in addition provide a sensitive indicator of specimen movement, astigmatism, and the damping-envelope constants Δ and
.
Misalignment of the electron beam , optic axis, and crystal axis in bright-field HREM work becomes increasingly important with increasing resolution and specimen thickness. The first-order effects of optical misalignment are an artifactual translation of spatial frequencies in the direction of misalignment by an amount proportional to the misalignment and to the square of spatial frequency. The corresponding phase shift is not observable in diffractograms. The effects of astigmatism on transfer functions for inclined illumination are discussed in Saxton (1978
).
The effects of misalignment of the beam with respect to the optic axis are discussed in detail by Smith, Saxton, O'Keefe, Wood & Stobbs (1983
), where it is found that all symmetry elements (except a mirror plane along the tilt direction) may be destroyed by misalignment. The maximum allowable misalignment for a given resolution δ in a specimen of thickness t is proportional to
Misalignment of a crystalline specimen with respect to the beam may be distinguished from misalignment of the optic axis with respect to the beam by the fact that, in very thin crystals, the former does not destroy centres of symmetry in the image.
The use of known defect point-group symmetry (for example in stacking faults) to identify a point in a HREM image with a point in the structure and so to resolve the black or white atomic contrast ambiguity has been described (Olsen & Spence, 1981
). Structures containing screw or glide elements normal to the beam are particularly sensitive to misalignment, and errors as small as 0.2 mrad may substantially alter the image appearance.
A rapid comparison of images of amorphous material with the beam electronically tilted into several directions appears to be the best current method of aligning the beam with the optic axis, while switching to convergent-beam mode appears to be the most effective method of aligning the beam with the crystal axis. However, there is evidence that the angle of incidence of the incident beam is altered by this switching procedure.
The effects of misalignment and choice of beam divergence
on HREM images of crystals containing dynamically forbidden reflections are reviewed by Nagakura, Nakamura & Suzuki (1982
) and Smith, Bursill & Wood (1985
). Here the dramatic example of rutile in the [001] orientation is used to demonstrate how a misalignment of less than 0.2 mrad of the electron beam with respect to the crystal axis can bring up a coarse set of fringes (4.6 Å), which produce an image of incorrect symmetry, since these correspond to structure factors that are forbidden both dynamically and kinematically.
Crystal thickness is most accurately determined from images of planar faults in known orientations, or from crystal morphology for small particles. It must otherwise be treated as a refinement parameter. Since small crystals (such as MgO smoke particles, which form as perfect cubes) provide such an independent method of thickness determination, they provide the most convincing test of dynamical imaging theory. The ability to match the contrast reversals and other detailed changes in HREM images as a function of either thickness or focus (or both) where these parameters have been measured by an independent method gives the greatest confidence in image interpretation. This approach, which has been applied in rather few cases [see, for example, O'Keefe, Spence, Hutchinson & Waddington (1985
)] is strongly recommended. The tendency for n-beam dynamical HREM images to repeat with increasing thickness in cases where the wavefunction is dominated by just two Bloch waves has been analysed by several workers (Kambe, 1982
).
Since electron scattering factors are proportional to the difference between atomic number and X-ray scattering factors, and inversely proportional to the square of the scattering angle (see Section 4.3.1
), it has been known for many years that the low-order reflections that contribute to HREM images are extremely sensitive to the distribution of bonding electrons and so to the degree of ionicity of the species imaged. This observation has formed the basis of several charge-density-map determinations by convergent-beam electron diffraction [see, for example, Zuo, Spence & O'Keefe (1988
)]. Studies of ionicity effects on HREM imaging can be found in Anstis, Lynch, Moodie & O'Keefe (1973
) and Fujiyoshi, Ishizuka, Tsuji, Kobayashi & Uyeda (1983
).
The depletion of the elastic portion of the dynamical electron wavefunction by inelastic crystal excitations (chiefly phonons, single-electron excitations, and plasmons) may have dramatic effects on the HREM images of thicker crystals (Pirouz, 1974
). For image formation by the elastic component, these effects may be described through the use of a complex `optical' potential and the appropriate Debye–Waller factor (see Section 2.5.1
). However, existing calculations for the absorption coefficients derived from the imaginary part of this potential are frequently not applicable to lattice images because of the large objective apertures used in HREM work. It has been suggested that HREM images formed from electrons that suffer small energy losses (and so remain `in focus') but large-angle scattering events (within the objective aperture) due to phonon excitation may contribute high-resolution detail to images (Cowley, 1988
). For measurements of the imaginary part of the optical potential by electron diffraction, the reader is referred to the work of Voss, Lehmpfuhl & Smith (1980
), and references therein. All evidence suggests, however, that for the crystal thicknesses generally used for HREM work (
200 Å) the effects of `absorption' are small.
In summary, the general approach to the matching of computed and experimental HREM images proceeds as follows (Wilson, Spargo & Smith, 1982
). (i) Values of Δ,
, and
are determined by careful measurements under well defined conditions (electron-gun bias setting, illumination aperture size, specimen height as measured by focusing-lens currents, electron-source size, etc). These parameters are then taken as constants for all subsequent work under these instrumental conditions (assuming also continuous monitoring of electronic instabilities). (ii) For a particular structure refinement, the parameters of thickness and focus are then varied, together with the choice of atomic model, in dynamical computer simulations until agreement is obtained. Every effort should be made to match images as a function of thickness and focus. (iii) If agreement cannot be obtained, the effects of small misalignments must be investigated (Smith et al., 1985
). Crystals most sensitive to these include those containing reflections that are absent due to the presence of screw or glide elements normal to the beam.
The general formulations for the dynamical theory of electron diffraction in crystals have been described in Chapter 5.2
of IT B (2001
). In Section 4.3.6
, the computing methods used for calculating diffraction-beam amplitudes have been outlined.
Given the diffracted-beam amplitudes,
, the image is calculated by use of equations (4.3.8.2)
, including, when appropriate, the modifications of (4.3.8.13b)
.
The numerical methods that can be employed in relation to crystal-structure imaging make use of algorithms based on (i) matrix diagonalization, (ii) fast Fourier transforms, (iii) real-space convolution (Van Dyck, 1980
), (iv) Runge-Kutta (or similar) methods, or (v) power-series evaluation. Two other solutions, the Cowley–Moodie polynomial solution and the Feynman path-integral solution, have not been used extensively for numerical work. Methods (i) and (ii) have proven the most popular, with (ii) (the multislice method) being used most extensively for HREM image simulations. The availability of inexpensive array processors has made this technique highly efficient. A comparison of these two N-beam methods is given by Self, O'Keefe, Buseck & Spargo (1983
), who find the multislice method to be faster (time proportional to
) than the diagonalization method (time proportional to
) for N
16. Computing space increases roughly as
for the diagonalization method, and as N for the multislice. The problem of steeply inclined boundary conditions for multislice computations has been discussed by Ishizuka (1982
).
In the Bloch-wave formulation, the lattice image is given by
where
and
are the eigenvector elements and eigenvalues of the structure matrix [see Hirsch, Howie, Nicholson, Pashley & Whelan (1977a
) and Section 4.3.4
].
Using modern personal computers or workstations, it is now possible to build efficient single-user systems that allow interactive dynamical structure-image calculations. Either an image intensifier or a cooled scientific grade charge-coupled device and single-crystal scintillator screen may be used to record the images, which are then transferred into a computer (Daberkow, Herrmann, Liu & Rau, 1991
). This then allows for the possibility of automated alignment, stigmation and focusing to the level of accuracy needed at 0.1 nm point resolution (Krivanek & Mooney, 1993
). An image-matching search through trial structures, thickness and focus parameters can then be completed rapidly. Where large numbers of pixels, large dynamic range and high sensitivity are required, the Image Plate has definite advantages and so should find application in electron holography and biology (Shindo, Hiraga, Oikawa & Mori, 1990
).
For the calculation of images of defects, the method of periodic continuation has been used extensively (Grinton & Cowley, 1971
). Since, for kilovolt electrons traversing thin crystals, the transverse spreading of the dynamical wavefunction is limited (Cowley, 1981
), the complex image amplitude at a particular point on the specimen exit face depends only on the crystal potential within a cylinder a few ångströms in diameter, erected about that point (Spence, O'Keefe & Iijima, 1978
). The width of this cylinder depends on accelerating voltage, specimen thickness, and focus setting (see above references). Thus, small overlapping `patches' of exit-face wavefunction may be calculated in successive computations, and the results combined to form a larger area of image. The size of the `artificial superlattice' used should be increased until no change is found in the wavefunction over the central region of interest. For most defects, the positions of only a few atoms are important and, since the electron wavefunction is locally determined (for thin specimens at Scherzer focus), it appears that very large calculations are rarely needed for HREM work. The simulation of profile images of crystal surfaces at large defocus settings will, however, frequently be found to require large amounts of storage.
A new program should be tested to ensure that (a) under approximate two-beam conditions the calculated extinction distances for small-unit-cell crystals agree roughly with tabulated values (Hirsch et al., 1977b
), (b) the simulated dynamical images have the correct symmetry, (c) for small thickness, the Scherzer-focus images agree with the projected potential, and (d) images and beam intensities agree with those of a program known to be correct. The damping envelope (product representation) [equation (4.3.8.17)
] should only be used in a thin crystal with
; in general, the effects of partial spatial and temporal coherence must be incorporated using equation (4.3.8.13a)
or (4.3.8.13b)
, depending on whether variations in diffraction conditions over
are important. Thus, a separate multislice dynamical-image calculation for each component plane wave in the incident cone of illumination may be required, followed by an incoherent sum of all resulting images.
The outlook for obtaining higher resolution at the time of writing (1997) is broadly as follows. (1) The highest point resolution currently obtainable is close to 0.1 nm, and this has been obtained by taking advantage of the reduction in electron wavelength that occurs at high voltage [equation (4.3.8.16)
]. A summary of results from these machines can be found in Ultramicroscopy (1994), Vol. 56, Nos. 1–3, where applications to fullerenes, glasses, quasicrystals, interfaces, ceramics, semiconductors, metals and oxides and other systems may be found. Fig. 4.2.8.6
shows a typical result. High cost, and the effects of radiation damage (particularly at larger thickness where defects with higher free energies are likely to be found), may limit these machines to a few specialized laboratories in the future. The attainment of higher resolution through this approach depends on advances in high-voltage engineering. (2) Aberration coefficients may be reduced if higher magnetic fields can be produced in the pole piece, beyond the saturation flux of the specialized iron alloys currently used. Research into superconducting lenses has therefore continued for many years in a few laboratories. Fluctuations in lens current are also eliminated by this method. (3) Electron holography was originally developed for the purpose of improving electron-microscope resolution, and this approach is reviewed in the following section. (4) Electron–optical correction of aberrations has been under study for many years in work by Scherzer, Crewe, Beck, Krivanek, Lanio, Rose and others – results of recent experimental tests are described in Haider & Zach (1995
) and Krivanek, Dellby, Spence, Camps & Brown (1997
). The attainment of 0.1 nm point resolution is considered feasible. Aberration correctors will also provide benefits other than increased resolution, including greater space in the pole piece for increased sample tilt and access to X-ray detectors, etc.
![[Figure 4.3.8.6]](/figures/Cbfig4o3o8o6thm.gif)
| Figure 4.3.8.6| top | pdf | Structure image of a thin lamella of the 6H polytype of SiC projected along [110] and recorded at 1.2 MeV. Every atomic column (darker dots) is separately resolved at 0.109 nm spacing. The central horizontal strip contains a computer-simulated image; the structure is sketched at the left. [Courtesy of H. Ichinose (1994).] |
The need for resolution improvement beyond 0.1 nm has been questioned – the structural information retrievable by a single HREM image is always limited by the fact that a projection is obtained. (This problem is particularly acute for glasses.) Methods for combining different projected images (particularly of defects) from the same region (Downing, Meisheng, Wenk & O'Keefe, 1990
) may now be as important as the search for higher resolution.
Since the resolution of an instrument is a property of the instrument alone, whereas the ability to distinguish HREM image features due to adjacent atoms depends on the scattering properties of the atoms, the resolution of an electron microscope cannot easily be defined [see Subsection 2.5.2.9
in IT B (2001
)]. The Rayleigh criterion was developed for the incoherent imaging of point sources and cannot be applied to coherent phase contrast. Only for very thin specimens of light elements for which it can be assumed that the scattering phase is −π/2 can the straightforward definition of point resolution
[equation (4.3.8.16)
] be applied. In general, the dynamical wavefunction across the exit face of a crystalline sample bears no simple relationship to the crystal structure, other than to preserve its symmetry and to be determined by the `local' crystal potential. The use of a dynamical `R factor' between computed and experimental images of a known structure has been suggested by several workers as the basis for a more general resolution definition.
For weakly scattering specimens, the most satisfactory method of measuring either the point resolution
or the information limit
[see equation (4.3.8.21)
] appears to be that of Frank (1975
). Here two successive micrographs of a thin amorphous film are recorded (under identical conditions) and the superimposed pair used to obtain a coherent optical diffractogram crossed by fringes. The fringes, which result from small displacements of the micrographs, extend only to the band limit
of information common to both micrographs, and cannot be extended by photographic processing, noise, or increased exposure. By plotting this band limit against defocus, it is possible to determine both Δ and
. As an alternative, for thin crystalline samples of large-unit-cell materials, the parameters Δ,
, and
can be determined by matching computed and experimental images of crystals of known structure. It is the specification of these parameters (for a given electron intensity and wavelength) that is important in describing the performance of high-resolution electron microscopes. We note that certain conditions of focus or thickness may give a spurious impression of ultra-high resolution [see equations (4.3.8.7)
and (4.3.8.8)
].
Within the domain of linear imaging, implying, for the most part, the validity of the WPO approximation, many forms of image processing have been employed. These have been of particular importance for crystalline and non-crystalline biological materials and include image reconstruction [see Section 2.5.5
in IT B (2001
)] and the derivation of three-dimensional structures from two-dimensional projections [see Section 2.5.6
in IT B (2001
)]. For reviews, see also Saxton (1980a
), Frank (1980
), and Schiske (1975
). Several software packages now exist that are designed for image manipulation, Fourier analysis, and cross correlation; for details of these, see Saxton (1980a
) and Frank (1980
). The theoretical basis for the WPO approximation closely parallels that of axial holography in coherent optics, thus much of that literature can be applied to HREM image processing. Gabor's original proposal for holography was intended for electron microscopy [see Cowley (1981
) for a review].
The aim of image-processing schemes is the restoration of the exit-face wavefunction, given in equation (4.3.8.13a)
. The reconstruction of the crystal potential
from this is a separate problem, since these are only simply related under the approximation of Subsection 4.3.8.3
. For a non-linear method that allows the reconstruction of the dynamical image wavefunction, based on equation (4.3.8.13b)
, which thus includes the effects of multiple scattering, see Saxton (1980b
).
The concept of holographic reconstruction was introduced by Gabor (1948
, 1949
) as a means of enhancing the resolution of electron microscopes. Gabor proposed that, if the information on relative phases of the image wave could be recorded by observing interference with a known reference wave, the phase modification due to the objective-lens aberrations could be removed. Of the many possible forms of electron holography (Cowley, 1994
), two show particular promise of useful improvements of resolution. In what may be called in-line TEM holography, a through-focus series of bright-field images is obtained with near-coherent illumination. With reference to the relatively strong transmitted beam, the relative phase and amplitude changes due to the specimen are derived from the variations of image intensity (see Van Dyck, Op de Beeck & Coene, 1994
). The tilt-series reconstruction method also shows considerable promise (Kirkland, Saxton, Chau, Tsuno & Kawasaki, 1995
).
In the alternative off-axis approach, the reference wave is that which passes by the specimen area in vacuum, and which is made to interfere with the wave transmitted through the specimen by use of an electrostatic biprism (Möllenstedt & Düker, 1956
). The hologram consists of a modulated pattern of interference fringes. The image wavefunction amplitude and phase are deduced from the contrast and lateral displacements of the fringes (Lichte, 1991
; Tonomura, 1992
). The process of reconstruction from the hologram to give the image wavefunction may be performed by optical-analogue or digital methods and can include the correction of the phase function to remove the effects of lens aberrations and the attendant limitation of resolution. The point resolution of electron microscopes has recently been exceeded by this method (Orchowski, Rau & Lichte, 1995
).
The aim of the holographic reconstructions is the restoration of the wavefunction at the exit face of the specimen as given by equation (4.3.8.13a)
. The reconstruction of the crystal potential
from this is a separate problem, since the exit-face wavefunction and
are simply related only under the WPO approximations of Subsection 4.3.8.3
. The possibility of deriving reconstructions from wavefunctions strongly affected by dynamical diffraction has been considered by a number of authors (for example, Van Dyck et al., 1994
). The problem does not appear to be solvable in general, but for special cases, such as perfect thin single crystals in exact axial orientations, considerable progress may be possible.
Since a single atom, or a column of atoms, acts as a lens with negative spherical aberration, methods for obtaining super-resolution using atoms as lenses have recently been proposed (Cowley, Spence & Smirnov, 1997
).
A number of non-conventional imaging modes have been found useful in electron microscopy for particular applications. In scanning transmission electron microscopy (STEM), powerful electron lenses are used to focus the beam from a very small bright source, formed by a field-emission gun, to form a small probe that is scanned across the specimen. Some selected part of the transmitted electron beam (part of the coherent convergent-beam electron diffraction pattern produced) is detected to provide the image signal that is displayed or recorded in synchronism with the incident-beam scan. The principle of reciprocity suggests that, for equivalent lenses, apertures and column geometry, the resolution and contrast of STEM and TEM images will be identical (Cowley, 1969
). Practical considerations of instrumental convenience distinguish particularly useful STEM modes.
Crewe & Wall (1970
) showed that, if an annular detector is used to detect all electrons scattered outside the incident-beam cone, dark-field images could be obtained with high efficiency and with a resolution better than that of the bright-field mode by a factor of about 1.4. If the inner radius of the annular detector is made large (of the order of 10−1 rad for 100 kV electrons), the strong diffracted beams occurring for lower angles do not contribute to the resulting high-angle annular dark-field (HAADF) image (Howie, 1979
), which is produced mainly by thermal diffuse scattering. The HAADF mode has important advantages for particular purposes because the contrast is strongly dependent on the atomic number, Z, of the atoms present but is not strongly affected by dynamical diffraction effects and so shows near-linear variation with Z and with the atom-number density in the sample. Applications have been made to the imaging of small high-Z particles in low-Z supports, such as in supported metal catalysts (Treacy & Rice, 1989
) and to the high-resolution imaging of individual atomic rows in semiconductor crystals, showing the variations of composition across planar interfaces (Pennycook & Jesson, 1991
).
The STEM imaging modes may be readily correlated with microchemical analysis of selected specimen areas having lateral dimensions in the nanometre range, by application of the techniques of electron energy-loss spectroscopy or X-ray energy-dispersive analysis (Williams & Carter, 1996
; Section 4.3.4
). Also, diffraction patterns (coherent convergent-beam electron diffraction patterns) may be obtained from any chosen region having dimensions equal to those of the incident-beam diameter and as small as about 0.2 nm (Cowley, 1992
). The coherent interference between diffracted beams within such a pattern may provide information on the symmetries, and, ultimately, the atomic arrangement, within the illuminated area, which may be smaller than the projection of the crystal unit cell in the beam direction. This geometry has been used to extend resolution for crystalline samples beyond even the information resolution limit, di (Nellist, McCallum & Rodenburg, 1995
), and is the basis for an exact, non-perturbative inversion scheme for dynamical electron diffraction (Spence, 1998
).
The detection of secondary radiations (light, X-rays, low-energy `secondary' electrons, etc.) in STEM or the detection of energy losses of the incident electrons, resulting from particular elementary excitations of the atoms in a crystal, in TEM or STEM, may be used to form images showing the distributions in a crystal structure of particular atomic species. In principle, this may be extended to the chemical identification of individual atom types in the projection of crystal structures, but only limited success has been achieved in this direction because of the relatively low level of the signals available. The formation of atomic resolution images using inner-shell excitations, for example, is complicated by the Bragg scattering of these inelastically scattered electrons (Endoh, Hashimoto & Makita, 1994
; Spence & Lynch, 1982
).
Reflection electron microscopy (REM) has been shown to be a powerful technique for the study of the structures and defects of crystal surfaces with moderately high spatial resolution (Larsen & Dobson, 1988
), especially when performed in a specially built electron microscope having an ultra-high-vacuum specimen environment (Yagi, 1993
). Images are formed by detecting strong diffracted beams in the RHEED patterns produced when kilovolt electron beams are incident on flat crystal surfaces at grazing incidence angles of a few degrees. The images suffer from severe foreshortening in the beam direction, but, in directions at right angles to the beam, resolutions approaching 0.3 nm have been achieved (Koike, Kobayashi, Ozawa & Yagi, 1989
). Single-atom-high surface steps are imaged with high contrast, surface reconstructions involving only one or two monolayers are readily seen and phase transitions of surface superstructures may be followed.
The study of surface structure by use of high-resolution transmission electron microscopes has also been productive in particular cases. Images showing the structures of surface layers with near-atomic resolution have been obtained by the use of `forbidden' or `termination' reflections (Cherns, 1974
; Takayanagi, 1984
) and by phase-contrast imaging (Moodie & Warble, 1967
; Iijima, 1977
). The imaging of the profiles of the edges of thin or small crystals with clear resolution of the surface atomic layers has also been effective (Marks, 1986
). The introduction of the scanning tunnelling microscope (Binnig, Rohrer, Gerber & Weibel, 1983
) and other scanning probe microscopies has broadened the field of high-resolution surface structure imaging considerably.
For many materials of organic or biological origin, it is possible to obtain very thin crystals, only one or a few molecules thick, extending laterally over micrometre-size areas. These may give selected-area electron-diffraction patterns in electron microscopes with diffraction spots extending out to angles corresponding to d spacings as low as 0.1 nm. Because the materials are highly sensitive to electron irradiation, conventional bright-field images cannot be obtained with resolutions better than several nanometres. However, if images are obtained with very low electron doses and then a process of averaging over the content of a very large number of unit cells of the image is carried out, images showing detail down to the scale of 1 nm or less may be derived for the periodically repeated unit. From such images, it is possible to derive both the magnitudes and phases of the Fourier coefficients, the structure factors, out to some limit of d spacings, say
. From the diffraction patterns, the magnitudes of the structure factors may be deduced, with greater accuracy, out to a much smaller limit,
. By combination of the information from these two sources, it may be possible to obtain a greatly improved resolution for an enhanced image of the structure. This concept was first introduced by Unwin & Henderson (1975
), who derived images of the purple membrane from Halobacterium halobium, with greatly improved resolution, revealing its essential molecular configuration.
Recently, several methods of phase extension have been developed whereby the knowledge of the relative phases may be extended from the region of the diffraction pattern covered by the electron-microscope image transform to the outer parts. These include methods based on the use of the tangent formula or Sayre's equation (Dorset, 1994
; Dorset, McCourt, Fryer, Tivol & Turner, 1994
) and on the use of maximum-entropy concepts (Fryer & Gilmore, 1992
). Such methods have also been applied, with considerable success, to the case of some thin inorganic crystals (Fu et al., 1994
). In this case, the limitation on the resolution set by the electron-microscope images may be that due to the transfer function of the microscope, since radiation-damage effects are not so limiting. Then, the resolution achieved by the combined application of the electron diffraction data may represent an advance beyond that of normal HREM imaging. Difficulties may well arise, however, because the theoretical basis for the phase-extension methods is currently limited to the WPO approximation. A summary of the present situation is given in the book by Dorset (1995
).