Structural, electronic and thermodynamic properties of BiF3-type Mg3Gd compound: A first-principle study.

Abstract: First-principle calculations based on density functional theory are adopted to investigate the structural, electronic and thermodynamic properties of BiF3-type Mg3Gd compound. Our results for the equilibrium structural parameters are consistent with experimental values and other theoretical results. The single-crystal elastic constants, polycrystalline elastic moduli, Poisson's ratio and anisotropy factor are determined using the Voigt–Reuss–Hill approximation. Estimated Cauchy pressure and the G/B relationship indicate that Mg3Gd is mechanically stable and brittle. In addition, the electronic structure is studied within the generalized gradient approximation (GGA) and local spin density approximation (LSDA) along with Hubbard energy. The calculations associated with phonon properties confirm the dynamical stability of BiF3-type structure. Finally, the dependences of normalized volume, bulk modulus and thermodynamic properties of Mg3Gd are obtained via the quasi-harmonic Debye model. [Copyright &y& Elsevier]