First-principles optical calculations of AsNMg3 and SbNMg3

The structural, electronic and optical properties of antiperovskite semiconductors AsNMg3 and SbNMg3 have been studied using the full-potential augmented plane wave plus local-orbital ( APW + lo ) method. The exchange correlation has been treated using the generalized gradient approximation (GGA). The equilibrium lattice constant and other structural properties have been determined. The AsNMg3 is found to be a direct band gap semiconductor while SbNMg3 is indirect. The results for electronic band structures, density of states, charge densities as well as optical properties are presented and discussed.