Ab initio study of boron nitride at high pressures

The results of first-principles calculations of the elastic, dielectric and dynamical properties for wurtzite BN are presented. The determination of the ground-state properties was performed within the local density approximation to the density functional theory, while the density functional perturbation theory is employed to derive the Born effective charges, high-frequency dielectric constants, and the phonon frequencies and eigenvectors. The influence of the pressure on the elastic and dielectric properties is examined and discussed. The pressure dependence of vibration modes was also investigated, leading to the determination of pressure coefficients. Our results agree generally well with the available data in the literature.