Structural, electronic, elastic and mechanical properties of NbC-based compounds: First-principles calculations

The structural, elastic, mechanical and electronic properties of NbC-based compounds have been investigated by first-principles calculations based on density functional theory. The crystal structure parameters were taken into account. The calculated results were coincident with the previous data. Through investigating the diagrams of DOS, the main contributions of electron's origin were obtained. The chemical bonds are confirmed by the Mulliken population and charge density maps. The independent elastic constants, bulk modulus, shear modulus, Young's modulus, ratio of B/G, and Poisson's ratio have been given. The mechanical stability and capacities to resist uniaxial tension, transformation of volume and plastic deformation of materials as well as ductile/brittle properties of NbC-based compounds were analyzed. Elastic anisotropy has been investigated. The obtained results reflect that all NbC-based compounds are elastically anisotropic.