Theoretical approaches to x-ray absorption fine structure
Abstract
Dramatic advances in the understanding of x-ray absorption fine structure (XAFS) have been made over the past few decades, which have led ultimately to a highly quantitative theory. This review covers these developments from a unified multiple-scattering viewpoint. The authors focus on extended x-ray absorption fine structure (EXAFS) well above an x-ray edge, and, to a lesser extent, on x-ray absorption near-edge structure (XANES) closer to an edge. The discussion includes both formal considerations, derived from a many-electron formulation, and practical computational methods based on independent-electron models, with many-body effects lumped into various inelastic losses and energy shifts. The main conceptual issues in XAFS theory are identified and their relative importance is assessed; these include the convergence of the multiple-scattering expansion, curved-wave effects, the scattering potential, inelastic losses, self-energy shifts, and vibrations and structural disorder. The advantages and limitations of current computational approaches are addressed, with particular regard to quantitative experimental comparisons.
- Publication:
-
Reviews of Modern Physics
- Pub Date:
- July 2000
- DOI:
- 10.1103/RevModPhys.72.621
- Bibcode:
- 2000RvMP...72..621R
- Keywords:
-
- 61.10.Ht;
- 32.30.Rj;
- 33.20.Rm;
- 78.70.Dm;
- 61.10.Ht;
- 32.30.Rj;
- 33.20.Rm;
- 78.70.Dm;
- X-ray absorption spectroscopy: EXAFS NEXAFS XANES etc.;
- X-ray spectra;
- X-ray spectra;
- X-ray absorption spectra;
- X-ray absorption spectroscopy: EXAFS NEXAFS XANES etc.;
- X-ray spectra;
- X-ray spectra;
- X-ray absorption spectra