The electronic structures of platinum dichalcogenides: PtS2, PtSe2and PtTe2

The band structures and density of states functions of platinum dichalcogenides, calculated using the LMTO-ASA method in conjunction with muffin-tin potentials, are reported for the first time. The results predict that PtS2 is a semiconductor with an energy gap of about 1.2 eV, PtSe2 is a semimetal with a slight indirect overlap of the conduction and valence bands, the PtTe2 is a metal with a complex Fermi surface. The electronic structures of these compounds are found to be substantially different from those of group IVb, Vb, and VIb TMDC having the same crystal structure. The results are discussed in terms of atomic orbital binding energies and the local coordination of the constituent atoms. The band structures obtained are generally in good agreement with the available experimental measurements.