First-principles study of the pressure-induced phase transition in CaTiO3

An investigation into the phase stabilities of CaTiO3 under high pressure was conducted using first-principles calculations based on density functional theory. We have identified three candidate structures of CaTiO3, Pbnm, Pm3m and Cmcm, respectively. Our results demonstrate that a phase transition from orthorhombic (Pbnm) to cubic (Pm3m) is impossible for CaTiO3 under high pressure at ambient temperature, and further predict that Pbnm-CaTiO3 will transform to post-perovskite phase (Cmcm) at enough temperature and pressure.