Dynamical Matrices and Interatomic-Force Constants from Wave-Commensurate Supercells

Abstract

We apply standard, first-principles calculations to a complete treatment of lattice dynamics in the harmonic approximation. The algorithm makes use of the straightforward ``frozen-phonon'' approach to the calculation of vibrational spectra and addresses some limitations of the method. Our prescription's validity is independent of crystal structure. It treats polar crystals in a general way, and it incorporates interatomic-force constants reaching beyond the supercell that is considered. For a range of materials, phonon dispersion exhibits the close agreement with experiment that is now characteristic of first-principles schemes. Results for graphite, Si and GaAs are presented.