Inelastic Scattering from Core-electrons: a Multiple Scattering Approach

TL;DR

This paper presents a real-space multiple-scattering approach to model non-resonant inelastic scattering from core electrons, applicable to various systems and energies, linking theoretical calculations with experimental spectra.

Contribution

It generalizes the multiple-scattering method to finite momentum transfer and incorporates ab initio electronic structure, enabling detailed analysis of inelastic scattering data from core electrons.

Findings

The approach accurately models inelastic scattering spectra across a broad energy range.

It relates inelastic loss spectra to X-ray absorption spectra in the dipole limit.

Finite momentum transfer calculations reveal higher-order multipole effects.

Abstract

The real-space multiple-scattering (RSMS) approach is applied to model non-resonant inelastic scattering from deep core electron levels over a broad energy spectrum. This approach is applicable to aperiodic or periodic systems alike and incorporates ab initio, self-consistent electronic structure and final state effects. The approach generalizes to finite momentum transfer a method used extensively to model x-ray absorption spectra (XAS), and includes both near edge spectra and extended fine structure. The calculations can be used to analyze experimental results of inelastic scattering from core-electrons using either x-ray photons (NRIXS) or electrons (EELS). In the low momentum transfer region (the dipole limit), these inelastic loss spectra are proportional to those from XAS. Thus their analysis can provide similar information about the electronic and structural properties of a system. Results for finite momentum transfer yield additional information concerning monopole, quadrupole, and higher couplings. Our results are compared both with experiment and with other theoretical calculations.