We describe a first-principles-based computational strategy for determination of the Landau-Devonshire potential. It exploits the configuration space attached to the eigenvectors of the modes frozen in the ground state. This allows to probe the energy surface in the vicinity of the ground state, which is most relevant for the properties of the ordered phase. We apply this procedure to BiFeO3 in order to determine potential energy associated with strain, polarization, and oxygen octahedra tilt.
Contact person: Pavel Márton