Comment on "Ab Initio Study of the Structural, Elastic, Electronic and Optical Properties of Cu₃N" [Materials Research. 2014;17(2):303-310]

Recently, Rahmati et al., ¹ have published a paper in Materials Research 2014; 17(2): 303-310. They have investigated the structural, elastic, electronic and optical properties of Cu₃N in its phase cubic anti-ReO₃ structure. But it is to be noted, that the numerical values of the density, the longitudinal (v_l), transverse (v_t) and average (v_m) elastic wave velocities, and the Debye temperature obtained by Rahmati et al., ¹ seem to be inaccurate. These errors are certainly due to the inaccuracy application of the formula used to calculate the density. In the present comment, we recalculated, and we gave the right numerical values of the density, the longitudinal (v_l), transverse (v_t) and average sound velocity (v_m) and of the Debye temperature of Cu₃N material, based on the lattice parameter and the elastic constants obtained in their work.

Keywords:
Copper nitride (Cu₃N) material; Sound velocity; Debye temperature