Approximate spherical wave thermal factors in XAFS

Abstract

We propose an approximate but rather accurate method to handle the thermal spherical wave (SW) effects in single and multiple scattering EXAFS spectra, and also in full multiple scattering XANES spectra. In contrast to EXAFS SW thermal factor, to resum the multiple scattering series, we assume the random cancellation for cross products of complicated multiple scattering terms which greatly simplifies the finite temperature XANES formula.