Rigid ion model of lattice dynamics - A re-evaluation

Abstract

A rigid ion model using an effective ionic charge gives reasonable agreement with phonon dispersion of crystals with NaCl, CsCl and zinc-blende structures. Model parameters are obtained from three elastic constants and two long-wavelength optic phonon frequencies. If the pressure dependence of these quantities is also available, the model may be readily used for the evaluation of mode Grüneisen parameters, Grüneisen constant and coefficient of thermal expansion.