First-principles lattice dynamical study of lanthanum nitride under pseudopotential approximation

The present paper reports a comprehensive first-principles calculation of lattice dynamical properties of lanthanum nitride, using the relativistic separable dual-space Gaussian pseudopotentials and local density approximation. Our results concerning equilibrium lattice parameter and bulk modulus agree well with the available experimental and previous theoretical data. The phonon dispersion curves and related properties in both ambient rocksalt (RS) and high pressure cesium chloride (CsCl) structures are reported for the first time which shows rocksalt as more stable structure similar to other calculations. The electronic and mechanical properties are also discussed.