Ab initio calculations of phonon dispersion relations for bulk and (110) surface of cubic InN

The ground-state structural and dynamical properties of cubic InN and its (110) surface are calculated using density functional theory within the generalised gradient approximation. A detailed discussion is provided for the energy location and atomic displacement pattern for characteristic surface phonon modes at symmetry points and along symmetry lines. The present surface phonon results are used to assess the level of success achieved by the application of an adiabatic bond charge model in a previous publication. By comparing the present results for InN(110) with a previous study of GaN(110), we are able to conclude that their dynamical behaviour is quite similar.