LMTO-ASA BAND-STRUCTURE CALCULATIONS OF BAVS3, BATIS3 AND THEIR SOLID-SOLUTIONS

Self-consistent electronic structure calculations for BaVS3, BaTiS3, B aV0.75Ti0.25S3, BaV0.5Ti0.5S3 and-hypothetical Ba0.5K0.5TiS3 compounds have been performed. It was shown that the Fermi level in BaVS3 lies on the narrow peak of density of states which is caused by Van Hove si ngularity coming from one-dimensional chains of V-atoms. Substitution of V-atoms by Ti ones leads to decrease density of states at Fermi lev el and loss of metallic properties of these compounds. It was found a considerable similarity of electronic structure of superconducting cup rates and that of hypothetical Ba0.5K0.5TiS3 which can be characterize d by the strong hybridization between Ti3d and S3p states and high den sity of S3p - states at the Fermi level.