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International
Tables for Crystallography Volume C Mathematical, physical and chemical tables Edited by E. Prince © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. C. ch. 4.2, p. 221
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Of the many theoretical data sets in existence, those of Storm & Israel (1970![[link]](/graphics/greenarr.gif)
), Cromer & Liberman (1970), and Scofield (1973) have often been used as bench marks against which both experimental and theoretical data have been compared. In particular, theoretical data produced using the S-matrix approach have been compared with these values. See, for example, Kissel, Roy & Pratt (1980). Some indication of the extent to which agreement exists between the different theoretical data sets is given in §4.2.6.2.4 (Tables 4.2.6.3(b) and 4.2.6.5). These tables show that the values of ![[f'(\omega,0)]](/teximages/cbch4o2/cbch4o2fi947.svg)
, which is proportional to σ, calculated using modern relativistic quantum mechanics, agree to better than 1%. It has also been demonstrated by Creagh & Hubbell (1987, 1990) in their analysis of the results of the IUCr X-ray Attenuation Project that there appears to be no rational basis for preferring one of these data sets over the other.
These tables do not list separately photo-effect cross sections. However, should these be required, the data can be found using Table 4.2.6.8. The cross section in barns/atom is related to expressed in electrons/atom by σ = 5636λ![[\,f'(\omega, 0),]](/teximages/cbch4o2/cbch4o2fi949.svg)
where λ is expressed in ångströms.
The values for ![[\sigma_{\rm pe}]](/teximages/cbch4o2/cbch4o2fi236.svg)
used in this compilation are derived from recent tabulations based on relativistic Hartree–Fock–Dirac–Slater calculations by Creagh. The extent to which this data set differs from other theoretical and experimental data sets has been discussed by Creagh (1990).
References
Creagh, D. C. (1990). Tables of X-ray absorption corrections and dispersion corrections: the new versus the old. Nucl. Instrum. Methods, A295, 417–434.Google Scholar
Creagh, D. C. & Hubbell, J. H. (1987). Problems associated with the measurement of X-ray attenuation coefficients. I. Silicon. Acta Cryst. A43, 102–112.Google Scholar
Creagh, D. C. & Hubbell, J. H. (1990). Problems associated with the measurement of X-ray attenuation coefficients. II. Carbon. Acta Cryst. A46, 402–408.Google Scholar
Cromer, D. T. & Liberman, D. (1970). Relativistic calculation of anomalous scattering factors for X-rays. J. Chem. Phys. 53, 1891–1898.Google Scholar
Kissel, L., Pratt, R. H. & Roy, S. C. (1980). Rayleigh scattering by neutral atoms, 100 eV to 10 MeV. Phys. Rev. A, 22, 1970–2004.Google Scholar
Scofield, J. H. (1973). Theoretical photoionization cross sections from 1 to 1500 keV. Report UCRL-51326. Lawrence Livermore National Laboratory, Livermore, CA, USA.Google Scholar
Storm, E. & Israel, H. I. (1970). Photon cross sections from 0.001 to 100 MeV for elements 1 through 100. Nucl. Data Tables, A7, 565–681.Google Scholar
