Density functional study of the thermodynamic properties and phase diagram of the magnesium hydride

This paper focuses primarily on the P-T phase diagram determination by considering six polymorphs of magnesium hydride (α - rutile TiO2, P42/mnm, β - cubic modified CaF2, Pa3¯, γ - orthorhombic PbO2, Pbcn, δ' - orthorhombic, Pbca and cubic - Fm3¯m). The Gibbs free energy and other thermodynamic properties were evaluated by DFT-based thermodynamic calculations, within the frame of the quasi-harmonic approximation, for the pressure range 0-10 GPa and temperatures between 0 and 1200 K. Furthermore, the structural, energetic, and electronic properties of the investigated structures are conversed.