Electric Polarization Field of Phonon Modes Induced by Pressure and Maximally-Localized Wannier Functions in Beryllium Chalcogenides: Theoretical Study

Abstract

We present a theoretical study of polaron properties associated to the optical phonon modes induced by pressure on the beryllium chalcogenides. The calculations are performed using abinitiopseudopotential approach based on the density functional perturbation theory combined with maximally–localized Wannier functions. Features such as phonon frequencies, dielectric constants, effective polar field, polaron effective mass, Fröhlich coupling constant, Debye temperature, deformation potential, polaron diffusion constant, and maximally–localized Wannier functions have been determined. Good agreement is found between our simulated results and available data. In another case, our calculated values are totally predictive. We show that the pressure dependence of those physico–chemical considerations on the electric polarization field is found to vary monotonously. These studies form the basis for further development of models to describe polaron transport in the monocrystalline phase of BeX (X = S, Se, and Te) compounds such as bulk crystals.