X-Ray Band Spectra and Electronic Structure of TiS2

Abstract

An electronic structure, in terms of molecular orbitals, is suggested for the layered compound Ti${\mathrm{S}}_2$. This structure is based on the combined $\mathrm{Ti}{L}_{\mathrm{III}}$, $\mathrm{Ti}K$, $\mathrm{S}{L}_{\mathrm{II},\mathrm{III}}$, and $\mathrm{S}K$ x-ray-emission and -absorption band spectra. The x-ray data appear to be compatible with the optical reflectivity spectrum but at odds with theoretical estimates of the band structure. Although the results are empirically conjectural they are used to suggest that Ti${\mathrm{S}}_2$ is a metal or semimetal instead of a small-gap semiconductor.