Lattice dynamics of single-bonded cubic nitrogen

The first principle calculations of the lattice dynamical properties of the single-bonded cubic nitrogen were performed using the density-functional perturbation theory together with plane-wave expansion and nonlocal pseudopotentials. The equilibrium structure of the single-bonded cubic nitrogen was first evaluated via the minimization of the total energy. Then, the harmonic phonon dispersion curves and the density of phonon states of the single-bonded cubic nitrogen have been evaluated within the linear-response framework. Furthermore, the heat capacity, enthalpy, free energy, entropy and velocity of sound of the single-bonded cubic nitrogen were calculated.