A first-principles pseudopotential investigation of ferroelectricity in barium titanate

Abstract We have investigated the adiabatic energy surface of BaTiO3 using a first-principles molecular dynamics approach. High quality pseudopotentials were generated for barium, titanium and oxygen using a recently developed ultra-soft pseudopotential scheme. The wave-functions were expanded in a plane-wave basis set, and adequate convergence was achieved with a 25 Ry cutoff. We show that the method gives a good description of the ferroelectric properties of BaTiO3 and agrees well with recent first-principles calculations performed using the full-potential linear-augmented-plane-wave method.