Open AccessMultiple‐electron excitation in X‐ray absorption: a simple generic model
Author(s) -
Roy M.,
Lindsay J. D.,
Louch S.,
Gurman S. J.
Publication year - 2001
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049501008160
Subject(s) - extended x ray absorption fine structure , atomic physics , excitation , electron , atomic orbital , absorption (acoustics) , limit (mathematics) , amplitude , simple (philosophy) , physics , electron excitation , chemistry , computational physics , absorption spectroscopy , quantum mechanics , mathematics , optics , mathematical analysis , philosophy , epistemology
The probability of multiple‐electron excitation in X‐ray absorption is calculated using a simple generic model. The model permits calculations to be made for all atoms with little input data or computing effort. The high‐energy limit of this probability, which gives the usual EXAFS amplitude reduction factor, is calculated in the `sudden approximation' using Slater orbitals. Good agreement with experiment is found. The energy dependence of this probability is also calculated using a simple model form of perturbing potential and found to agree well with experiment for rare gas atoms. The effect on the X‐ray absorption coefficient of including multiple‐electron excitations is also determined and is found to be small, again in agreement with observation.