Theoretical investigations of structural, mechanical, electronic and optical properties of NaScSi alloy

Ab initio density functional theory is employed to investigate the structural, elastic, electronic and optical properties of the half-Heusler NaScSi alloy. The lattice constants are very near to the available theoretical data. In addition, besides the GGA approximation, the modified Becke–Johnson exchange potential is also used to improve the direct X→X band gap value. Furthermore, the elastic constants and related elastic moduli confirm its stability and brittle behaviour in the type I structure. The influence of pressure on Cij constants, bulk modulus B, Cauchy pressure, Poisson ratio ν, shear modulus, B/G ratio and anisotropy factor A are analysed. Additionally, the strong absorption is extended between the visible domain and that of the ultraviolet is predicted.