Surface rumpling of cubic CaTiO₃ from density functional theory

In this paper, the structure of cubic CaTiO₃ (001) surfaces with CaO and TiO₂ terminations has been studied from density functional calculations. It has been found that the Ca atom has the largest relaxation for both kinds of terminations, and the rumpling of the CaO-terminated surface is much larger than that of TiO₂-terminated surface. Also we have found that the metal atom relaxes much more prominently than the O atom does in each layer. The CaO-terminated surface is slightly more energetically favourable than the TiO₂-terminated surface from the analysis of the calculated surface energy.