摘要

Structures of transition metal nitrides (TMNs) were optimized using the plane-wave pseudopotential method based on density functional theory. Energy as a function of volume curves were calculated to predict the phase transition pressures. Density of states (DOS), charge density difference; and charge transfers were calculated. The elastic constant (C-11) and modulus (G) as a function of pressure were computed. Results showed that TMNs in the WC structure was most stable at normal pressure. All TMNs exhibited metallic, covalent and ionic property. Metallic character increased and covalent property reduced with increasing atomic number of TM atom. The elastic constant (C-11) and modulus (G) increased linearly with increasing pressure due to stronger hybridization, bonding and covalent property. Thus, mechanical property enhanced under external pressure.

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