First principles study of CaTiO3 crystal in paraelectric and ferroelectric phases

Electronic properties of CaTiO3 crystal in paraelectric and ferroelectric phases have been studied by first principles, using Hohenberg-Kohn-Sham density functional theory (DFT). In paraelectric phase the results show an indirect band gap of about 2eV at -R direction in the Brilluoin zone and a strong hybridization between Ti-3d an O-2P orbital. In ferroelectric phase a direct band gap of about 1eV is seen at point. Up to our knowledge no data has been reported on the ferroelectric phase so far, therefore our results might be useful for the future works.