Interpretation of preedge features in the Ti and S K-edge x-ray-absorption near-edge spectrain the layered disulfidesTiS2andTaS2

The electronic structure of the layered titanium and tantalum disulfides ${\mathrm{TiS}}_2$ and ${\mathrm{TaS}}_2$ is investigated by the experimental sulfur and titanium K-edge x-ray-absorption near-edge structures, full multiple-scattering theory, and tight-binding linear muffin-tin orbital band-structure method. Good agreement between experimental data and theoretical calculations is obtained, especially in preedge regions that are interpreted in terms of mixing between the central atom p and higher-neighboring metal d orbitals. The variation of width and intensity of the prepeak is associated with the occupation of the d band and linked with metal site symmetry.