The investigation of the structural, electronic, elastic and thermodynamic properties of TbX (X = As, Bi, N, P, Sb) and Na2Se compounds by ab-initio method

In this study, some structural, electronic, elastic and thermodynamic properties of TbX (X = As, Bi, N, P, Sb) and Na2Se compounds were calculated by using the generalized gradient (GGA) approximation with ab-initio method based on plane-wave pseudopotentials and density functional theory. For these compounds, the lattice parameters, GGA+U effectives in lattice parameters, formation enthalpies, phase transitions, band structures, partial and total density of states (DOS) curves, elastic constants, pressure variations and GGA+U effectives in elastic constants, Zener anisotropy factors, Poisson ratios, Young and Shear modulus, Debye and Melting temperatures, sound velocities were calculated. In addition, the pressure and temperature dependence of some thermodynamic properties were also investigated. The obtained results were compared with the available experimental and theoretical data. The results showed that the used method gave the accurate results for compound properties.