Elastic properties and electronic structures of 4d- and 5d-transition metal mononitrides

Elastic properties and electronic structures of 4d-transition metal mononitrides (ZrN, NbN, MoN, TcN, RuN, RhN, PdN, and AgN) and 5d-transition metal mononitrides (HfN, TaN, WN, ReN, OsN, IrN, PtN, and AuN) with both rocksalt and zinc-blende structures have been investigated by first-principles calculations. Lattice constants, bulk moduli, band structures and cohesive energies are obtained. The trends of lattice constants, cohesive energies and electronic properties as a function of the number of d electrons are revealed. The relationships of cohesive energies as a function of unit-cell volume and the transition pressures of zinc-blende-to-rocksalt phase transformations are also discussed.