Systematic trends in (001) surface ab initio calculations of ABO3 perovskites

By means of the hybrid exchange-correlation functionals, as it is implemented in the CRYSTAL computer code, ab initio calculations for main ABO(3) perovskite (0 0 1) surfaces, namely SrTiO3, BaTiO3, PbTiO3, CaTiO3, SrZrO3, BaZrO3, PbZrO3 and CaZrO3, were performed. For ABO(3) perovskite (001) surfaces, with a few exceptions, all atoms of the upper surface layer relax inward, all atoms of the second surface layer relax outward, and all third layer atoms, again, inward. The relaxation of (0 0 1) surface metal atoms for ABO(3) perovskite upper two surface layers for both AO and BO2 -terminations, in most cases, are considerably larger than that of oxygen atoms, what leads to a considerable rumpling of the outermost plane. The ABO(3) perovskite (0 0 1) surface energies always are smaller than the (0 1 1) and especially (111) surface energies. The ABO(3) perovskite AO and BO2-terminated (0 0 1) surface band gaps always are reduced with respect to the bulk values. The B-O chemical bond population in ABO(3) perovskite bulk always are smaller than near the (0 0 1) and especially (0 11) surfaces. (C) 2017 King Saud University. Production and hosting by Elsevier B.V.