Lattice dynamics of CuAlO2 under high pressure from ab initio calculations

The density functional perturbation theory is employed to study the vibrational properties of CuAlO2 under pressure. The calculations are preformed using the pseudopotential wave method and the local density approximation for the exchange-correlation (XC) potential. The d electrons of Cu are treated as valence states. We present the phonon dispersion curves. Our results are in good agreement with the available experimental Raman scattering experiments. A initio calculations show the presence of a dynamical instability, possibly related with the experimentally observed phase transition.