Ab initio study of the structural and electronic properties of Nb2AlC

The structural and electronic properties of Nb2AlC have been studied using the ab initio pseudopotential approach based on density functional theory. The internal coordinates of Nb atom is determined to be (1/3, 2/3, 0.089). The equilibrium lattice parameters are computed to be a = 3.119 Å and c = 13.92 Å, in good agreement with experimental results. The band structure and density of states reveal that Nb2AlC is an electronic conductor. Both Nb 4d and Al 3p contribute to the electronic properties. Partial density of state indicates that a strong hybridization of Nb 4d and C 2p states. The charge density distribution shows that the Nb and C atoms form a strong NbCNb covalently bonded chain.