Recent Developments in the Analysis of X-Ray Raman Scattering

Non-resonant inelastic scattering of hard x-rays from core-electron excitations is often called x-ray Raman scattering (XRS). In the low momentum transfer limit, the XRS spectrum is proportional to the x-ray absorption coefficient. However, additional information is available when the magnitude of the momentum transfer is increased in XRS experiments. In this paper we will review recent developments in first-principles methods to analyze XRS spectra. Additionally, the importance of the momentum transfer dependent single-particle excitation matrix elements in the analysis will be discussed. We show how the momentum transfer dependence of the spectra can be used to extract information on the spatial symmetries of the final state electrons. We demonstrate this on experimental data for the Li K edge in Li metal.