Electronic structure of the misfit layer compound : band structure calculations and photoelectron spectra

In order to understand the electronic structure of the incommensurate misfit layer compound (SnS)1.20TiS2 we carried out an ab initio band structure calculation in the supercell approximation. The band structure is compared with that of the components 1T-TiS2 and hypothetical SnS with a similar structure as in (SnS)1.20TiS2. The calculations show that the electronic structure is approximately a superposition of the electronic structures of the two components TiS2 and SnS, with a small charge transfer from the SnS layer to the TiS2 layer. The interlayer bonding between SnS and TiS2 is dominated by covalent interactions. X-ray and ultraviolet photoelectron spectra of the valence bands are in good agreement with the band structure calculation.