First-principles study on the tendency to ferroelectricity of CaTiO3

The electronic structure of incipient ferroelectric CaTiO3 is presented. The full potential linearized augmented plane wave method is used and exchange-correlation effects are treated by the generalized gradient approximation. In order to understand the incipient ferroelectricity of CaTiO3, the total energy, the density of states, the electric field gradient (EFG) and the band structure were calculated. From the total energy analysis, we conclude that CaTiO3 has a tendency to ferroelectricity. This is consistent with the analysis of the EFG. Like other perovskite ABO3 ferroelectrics, there is a hybridization between Ti 3d and O 2p, which is responsible for the tendency to ferroelectricity.