Angle-dependent x-ray sulfur $K$-emission bands and electronic structure of ${\mathrm{SnS}}_2$ and ${\mathrm{MoS}}_2$

The angular dependence of polarized S $K$-emission bands of ${\mathrm{SnS}}_2$ and ${\mathrm{MoS}}_2$ was studied with the use of x-ray emission spectroscopy (XES). By application of the self-consistent pseudopotential method, the band structure, the local partial densities of states, and the x-ray bands were calculated. Good agreement between experiment and theory has been observed. The $s$,$p$,$d$ character and localization of valence electrons are identified, and the shape of spectra is fully explained. The particular role of $d$-like electrons in the Mo—S bond and the Mo $L{\beta }_2$-emission bands is discussed. The relations between core states, valence states, and polarization of radiation are analyzed. The results are compared with available XES, and x-ray and ultraviolet photoelectron spectroscopy measurements.