The electronic structure of hexagonal BaCoO3

TB-LMTO-ASA band structure calculations within the local spin density approximation have been performed to explain the magnetic and transport properties of BaCoO₃. The calculations predict a magnetic and metallic ground state as energetically favored. BaCoO₃ shows no long-range magnetic ordering, however, and only poor conductivity. The magnetic energy is low and the compound shows glassy susceptibility behavior at low temperatures. From the band structure we find Mott-Hubbard localization to be unlikely, and instead propose Anderson localization as a possible origin of the observed behavior. Calculations on slightly distorted structures exclude the possibility of a Peierls distortion.