Ca and S K-edge XANES of CaS calculated by different methods: influence of full potential, core hole and Eu doping

TL;DR

This study compares different computational methods for Ca and S K-edge XANES spectra of CaS, examining effects of full potential, core hole, and Eu doping, revealing minimal differences among methods and limited impact of doping.

Contribution

It systematically evaluates the influence of computational choices and Eu doping on CaS XANES spectra, providing insights into modeling accuracy and doping effects.

Findings

Different methods produce similar spectra with minor differences near the edge.

Full potential calculations do not significantly improve results over atomic spheres approximation.

Eu doping introduces a pre-edge feature without substantially altering the spectra.

Abstract

Ca and S K-edge spectra of CaS are calculated by the full-potential Green's function multiple-scattering method, by the FLAPW method, and by the finite difference method. All three techniques lead to similar spectra. Some differences remain close to the edge, both when comparing different calculations with each other and when comparing the calculations with earlier experimental data. We find that using the full potential does not lead to significant improvement over the atomic spheres approximation and that the effect of the core hole can be limited to the photoabsorbing atom alone. Doping CaS with Eu will not affect the Ca and S K-edge XANES of CaS significantly but may give rise to a pre-edge structure not present for clean CaS.