Temperature dependence of the phonon frequencies of molybdenum:: a tight-binding molecular dynamics study

The phonon dispersion curves of molybdenum at zero temperature as well as at elevated temperatures are studied, using our recently developed semi-empirical tight-binding model. At zero temperature the phonon dispersion curves are obtained by frozen-phonon calculations as well as by a dynamical matrix approach. The phonon frequency shifts due to an increase in temperature are calculated by molecular dynamics (MD) simulations and the quasiharmonic contribution to the total frequency shift is determined. An alternative approach for calculating the frequency shifts without performing MD simulations is also presented.