Theoretical study of structural and electronic properties ofδ-MoN

Using density functional theory within the local density approximation and generalized gradient approximation, we compare the cohesive energy of molybdenum nitride in its hexagonal $\ensuremath{\delta}$-phase with that in the NiAs structure from which it differs by small distortions. The energy bands and bulk modulus are calculated, the latter in good agreement with experiment. Although $\ensuremath{\delta}$-MoN is a metal, we find a large ionic component to its bonding.