ELECTRONIC-STRUCTURE OF MERCURY-BASED HIGH-T(C) COMPOUNDS - HGBA2CAN-1CUNO2N+2(N=1,2,3)

A fist principles determination of the electronic structure of the tetragonal mercury-based compounds containing one Hg plane, HgBa2CuO4 (Hg1201), HgBa2CaCu2O6 (Hg1212) and HgBa2Ca2Cu3O8 (Hg1223), has been made within the local-density approximation using the full potential linear muffin tin orbital method. The band structures exhibit overall features similar to those of other cuprate superconductors with a marked peculiarity: an antibonding band coming mostly from the hybridization of Hg-p and d and apical oxygen (O2)-p states which lies slightly above the Fermi level for Hg1201 and below it for Hg1212 and Hg1223, but whose exact position depends on the relative z-position of apical O2 atoms within the unit cell. This detail is important to establish the degree of self-doping in these compounds.