A comparative ab initio study of bulk and surface oxygen vacancies in PbTiO3, PbZrO3 and SrTiO3 perovskites

Using the DFT-HF hybrid LCAO approach as implemented in the CRYSTAL   computer code, we have performed large supercell comparative calculations of neutral O vacancies (FF centers) in the bulk and on the (001) surface of three cubic perovskite crystals (SrTiO3, PbTiO3, and PbZrO3). The local lattice relaxation, charge redistribution, and positions of defect energy levels within the band gap are compared. It is shown that the difference in the chemical composition of host materials leads to quite different defect properties.