Raman spectra and lattice dynamics of cubic gauche nitrogen.

The lattice dynamical properties of the cubic gauche phase of nitrogen are computed using density functional perturbation theory. The structure is found to be stable up to at least 250 GPa. Based on the dynamical data we derive the thermodynamical properties. We also determine the Raman spectra with both peak position and intensity and find excellent agreement with the experimental data, with the A mode dominating the spectra at all pressures.