First-principles calculations of the structural and electronic properties of Cu_3MN compounds with M = Ni, Cu, Zn, Pd, Ag, and Cd

摘要

We have performed accurate ab initio total energy calculations using the full-potential linearized augmented plane wave (FP-LAPW) method to investigate the structural and electronic properties of copper-transition metal nitrides. In its ground state, Cu_3N crystallizes in an anti-ReO_3 type cell and it is a semiconductor material with a small indirect gap. In this paper, we report a study of Cu_3MN compounds with M = Ni, Cu, Zn, Pd, Ag, and Cd. In the calculations, we have used the same anti-ReO_3 type cell of Cu_3N, but with the extra transition metal atom at the center of the cube. In particular, our calculated lattice parameters for copper nitride (a = 3.82 A) and copper palladium nitride (a = 3.89 A) are in excellent agreement with the experimental values of a = 3.807 A and a = 3.86 A, respectively. In all the cases we have studied, the addition of the transition metal atom modifies the electronic structure of Cu_3N, turning all copper-transition metal nitrides into metals.