STRUCTURAL-PROPERTIES AND ELECTRONIC-STRUCTURE OF HGBA2CUO4 - DETAILED DESCRIPTION OF THE FERMI-SURFACE

An ab initio determination of the structural properties and electronic structure of tetragonal HgBa2CuO4 has been made, within the local-density approximation using the full-potential linear-muffin-tin-orbital method. We find good agreement with the experimental lattice constant and c/a ratio. The band structure exhibits overall features similar to those of other cuprate superconductors with a marked peculiarity, that of an antibonding band coming from the hybridization of Hg p and d and apical oxygen O(2)p states, which lies slightly on top of the Fermi level (E(F)) This feature has some similarity to what happens in Tl2Ba2CuO6. Within this framework a comprehensive description of the character of the states close to and at the Fermi surface is presented.