Application of a Kohn-Sham-like formulation of the self-consistent atomic deformation model

Abstract

The self-consistent atomic deformation model is applied to compounds selected to illustrate two important features of the model: 1) The formulation of the potential from a Kohn-Sham like variational treatment of the total energy produces atomic energy levels which obey Janak's theorem. This feature is illustrated by results for LaSrCuO4 with the ions constrained to be spherical. 2) The importance of non-spherical distortions of oxygen ions in ferroelectric oxides is demonstrated with results for BaTiO3 and KNbO3. Born effective charges are computed and compared with previous calculations for these compounds and the alkaline earth oxides.