Ab Initio Calculations of Phonon Dispersion in ZnGa2Se4

In the context of density functional theory, the phonon density of states and phonon dispersion are calculated for ZnGa2Se4. The temperature dependence of the heat capacity of ZnGa2Se4 in the temperature range 5-400 K is obtained. The calculated frequencies and symmetries of phonon modes in the center of the Brillouin zone are in good agreement with experimental data obtained by Raman spectroscopy and infrared spectroscopy.