Structural, elastic, thermodynamic and electronic properties of LuX (X = N, Bi and Sb) compounds: first principles calculations

The structural, electronic, elastic and thermodynamic properties of LuX (X = N, Bi and Sb) based on rare earth into phases, Rocksalt (B1) and CsCl (B2) have been investigated using full-potential linearized muffintin orbital method (FP-LMTO) within density functional theory. Local density approximation (LDA) for exchange-correlation potential and local spin density approximation (LSDA) are employed. The structural parameters as lattice parameters a(0), bulk modulus B, its pressure derivate B' and cut-off energy (E-c) within LDA and LSDA are presented. The elastic constants were derived from the stress - strain relation at 0 K. The thermodynamic properties for LuX using the quasi-harmonic Debye model are studied. The temperature and pressure variation of volume, bulk modulus, thermal expansion coefficient, heat capacities, Debye temperature and Gibbs free energy at different pressures (0 - 50 GPa) and temperatures (0 - 1600 K) are predicted. The calculated results are in accordance with other data.