A quantum-chemical study of technologically important BaTiO3 crystal and O-vacancy defects on its (001) surface was reported. The computations were made by using a quantum-chemical method developed for periodic systems (crystals), which was based upon the Hartree–Fock theory. The atomic rearrangement due to the surface creation was obtained for a pure BaTiO3 by means of the periodic large unit cell model and by using an automated geometry optimization procedure. The same technique was employed to study the electronic and structural properties of the material due to the presence of an O vacancy and F center (two electrons trapped in an O vacancy). The computations were carried out for both cubic and tetragonal lattices.

Oxygen-Vacancy Defects on BaTiO3 (001) Surface - a Quantum Chemical Study. C.Duque, A.Stashans: Physica B, 2003, 336[3-4], 227-35