MAX phases Nb2AC (AÂ =Â S, Sn): An ab initio study

► Elastic, electronic, thermal and optical properties of Nb2SC in comparison to Nb2SnC. ► First time analysis of thermodynamic (finite T and P) and optical properties. ► Estimated λ-values show Nb2SC and Nb2SnC to be moderately coupled SC. ► Band structure shows metallic conductivity with major contribution from Nb 4d states. ► Nb2SC is a better dielectric, but both should act as good coating materials.