Final-State Rule vs. the Bethe-Salpeter Equation for Deep-Core X-ray Absorption Spectra
J J. Rehr, J A. Soininen, Eric L. Shirley
The independent-electron approximation together with the final-state rule provides a well established method for calculating x-ray absorption spectra that takes into account both core-hole effects and inelastic losses. Recently a Bethe-Salpeter Equation approach based on Hedin's GW approximation that explicitly treats particle-hole excitations has been applied to the same problem. We discuss here the formal relationships between these approaches for deep-core x-ray spectra and show that they are similar, apart from differences in their practical implementations. Their similarity is illustrated with results from both theoretical approaches and compared with experiment. This comparison also suggests ways to improve these approaches.
final state, k-edge, x-ray absorption
, Soininen, J.
and Shirley, E.
Final-State Rule vs. the Bethe-Salpeter Equation for Deep-Core X-ray Absorption Spectra, Physica Scripta
(Accessed June 10, 2023)