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

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. Here it is found 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. There are differences between theoretical and experimental Ca and S K‐edge XANES of CaS within the first 10 eV above the edge that cannot be explained as full‐potential effects or by the influence of the core hole as accounted for by the final‐state rule.