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Comparative First-Principles Calculations of SrTiO3, BaTiO3, PbTiO3 and CaTiO3 (001), (011) and (111) Surfaces

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I present the results of my ab initio calculations for SrTiO3, BaTiO3, PbTiO3 and CaTiO3 neutral (001), as well as for polar (011) and (111) surfaces using the hybrid description of exchange and correlation. AO and BO2-terminations for the nonpolar (001) surface and A, BO, and O terminations of the polar (011) surface, as well as B and AO3-terminations of the polar (111) surface were calculated. In the case of the neutral AO-terminated (001) surface for SrTiO3, BaTiO3, PbTiO3 and CaTiO3 perovskites, all upper-layer A atoms relax inward towards the bulk, while all second layer atoms relax outwards. For the BO2-terminated (001) surface, in most cases, the largest relaxations are on the second-layer metal atoms. For practically all ABO3 perovskites, the surface rumpling is considerably larger for the AO-terminated than for the BO2-terminated (001) surface, but their surface energies always are almost equal. Just opposite, different terminations of the (011) ABO3 surface lead to very different surface energie...