Electronic structure of quasi-one-dimensional BaVS3

Abstract Linear augmented-plane-wave band-structure results for hexagonal BaVS 3 , a quasione-dimensional (1D) sulfide with chains of face-sharing VS 6 octahedra, exhibit partially filled t 2g conduction bands containing narrow (∼0.7 eV) d xy -d x 2 −y 2 levels amid broader (∼3.0 eV) d 3z 2 −r 2 subbands, but only faint 1D characteristics. The Fermi level is pinned on the low-energy shoulder of a d xy -d x 2 −y 2 density-of-states peak. The observed hexagonal-orthorhombic distortion (∼240K) fails to open a band gap at E F , thus precluding a band explanation for the metal-insulator transition that occurs at low (∼70K) temperatures.