Mechanical properties and electronic structure of anti-ReO₃ structured cubic nitrides, M₃N, of d block transition metals M: An ab initio study

Highlights: • We use DFT to model the anti-ReO₃ structured transition metal nitrides M₃N. • We predict their lattice constants, electronic structures and mechanical properties. • We correlate the metal d and nitrogen 2p orbitals with stability and hardness. • We established a high-throughput database for materials design. - Abstract: We report a systematic study of the anti-ReO₃ structured transition metal nitrides, M₃N, using ab initio density functional theory computations in the local density approximation. Here M denotes all the 3d, 4d and 5d transition metals. Our calculations indicate that all M₃N compounds except V₃N of group 5 and Zn₃N and Hg₃N of group 12 are mechanically stable. For the stable M₃N compounds, we report a database of predictions for their lattice constants, electronic properties and mechanical properties including bulk modulus, Young’s modulus, shear modulus, ductility, hardness and Debye temperature. It is found that most M₃N compounds exhibit ductility with Vickers hardness between 0.4 GPa and 11.2 GPa. Our computed lattice constant for Cu₃N, the only M₃N compound where experiments exist, agrees well with the experimentally reported values. We report ratios of the melting points of all M₃N compounds to that of Cu₃N. The local density of states for all M₃N compounds are obtained, and electronic band gaps are observed only for M of group 11 (Cu, Ag and Au) while the remaining M₃N compounds are metallic without band gaps. Valence electron density along with the hybridization of the metal d and nitrogen 2p orbitals play an important role in determining the stability and hardness of different compounds. Our high-throughput databases for the cubic anti-ReO₃ structured transition metal nitrides should motivate future experimental work and shorten the time to their discovery