CNDO studies of Y-Ba-Cu-O superconductors I. Comparative study of CuOn polyhedra

Research paper by Martin Breza

Indexed on: 01 Feb '92Published on: 01 Feb '92Published in: Czechoslovak Journal of Physics


Electronic structure of CuOnq clusters (n=2, 4, 5) is calculated in experimental geometries of YBa2Cu3O6 and YBa2Cu3O7 for various formal oxidation states of Cu modelled by total cluster charges,q, both by non-relativistic and by quasi-relativistic CNDO and INDO methods. The results for standard Cu (d10s1p0) as well as for nonstandard Cu (d9s2p0) reference configurations are compared from the point of view of the Cu oxidation state. Cu (III) oxidation state seems to be improbable.