Table 2.1.1

Helliwell, J. R.

doi:10.1107/97809553602060000576

International
Tables for
Crystallography
Volume C
Mathematical, physical and chemical tables
Edited by E. Prince

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International Tables for Crystallography (2006). Vol. C. ch. 2.1, p. 25

Table 2.1.1

J. R. Helliwell^a

^a Department of Chemistry, University of Manchester, Manchester M13 9PL, England

Table 2.1.1 | top | pdf |
Summary of main experimental techniques for structure analysis

Name of technique	Beam		Sample	Usual detectors
Name of technique	Usual type	Spectrum	Sample	Usual detectors
(A) Single crystal
Laue	X-ray or neutron	Polychromatic	Stationary single crystal	Film; image plate or storage phosphor; electronic area detector (e.g. CCD); for neutron case, detector sensitive to time-of-flight
Still	X-ray or neutron or electron	Monochromatic	Stationary single crystal	Film; image plate or storage phosphor; electronic area detector (e.g. MWPC, TV, CCD)
Rotation/oscillation	X-ray	Monochromatic	Single crystal rotating about a single axis (typical angular range per exposure 5–15° for small molecule; 1–2° for protein; 0.25–0.5° for virus)	Film; image plate or storage phosphor; electronic area detector (e.g. MWPC, TV, CCD)
Weissenberg	X-ray	Monochromatic	Single crystal rotating about a single axis (angular range $[\ge]$ 15°), coupled with detector translation	Film; image plate or storage phosphor
Precession	X-ray	Monochromatic	Single crystal (the normal to a reciprocal-lattice plane precesses about X-ray beam)	Flat film moving behind a screen coupled with crystal so as to be held parallel to a reciprocal-lattice plane
Diffractometry	X-ray or neutron	Monochromatic	Single crystal rotated over a small angular range	Single counter, linear detector or area detector
(B) Polycrystalline powders
Monochromatic powder method	X-ray or neutron or electron	Monochromatic	Powder sample rotated to increase range of orientations presented to beam	Film or image plate; counter; 1D position-sensitive detector (linear or curved)
Energy-dispersive powder method	X-ray or neutron	Polychromatic	Powder sample	Energy-dispersive counter (for neutron case, detector sensitive to time-of-flight)
(C) Fibres, solutions, surfaces, and membranes
Fibre method	X-ray or neutron	Monochromatic	Single fibre or a bundle of fibres; preferred orientation in a sample	Film or image plate; electronic area detector (e.g. MWPC or TV); records high-angle or low-angle diffraction data
Solution or `small-angle method'	X-ray or neutron	Monochromatic	Dilute solutions of particles; crystalline defects	Counter or MWPC
Surface diffraction	Electron or X-ray	Monochromatic	Atoms deposited or adsorbed onto a substrate	Phosphor or counter
Membranes	Electron or X-ray	Monochromatic	Naturally occurring 2D ordered membrane protein	Film or image plate; CCD

Notes

(1) Monochromatic. Typical value of spectral spread, $[\delta\lambda/\lambda]$ , on a conventional X-ray source; $[K\alpha_1-K\alpha_2]$ line separation $[\sim2.5\times10^{-3}]$ , $[K\alpha_1]$ line width $[\sim10^{-4}]$ . On a synchrotron source a variable quantity dependent on type of monochromator; typical values $[\sim\!10^{-3}]$ or $[\sim\!10^{-4}]$ for the two common monochromator types (see Figs. 2.2.7.2 and 2.2.7.3 , respectively).
(2) CCD = charge-coupled device; MWPC = multiwire proportional chamber detector; TV = television detector.
(3) Image plate is a trade name of Fuji. Storage phosphor is a trade name of Kodak.
(4) EXAFS can be performed on all types of sample whether crystalline or noncrystalline. It uses an X-ray beam that is tuned around an absorption edge and the transmitted intensity or the fluorescence emission is measured.