Pressure effect on the structural, elastic and thermodynamic properties of the BeP2N4 compound: First-principles investigation

Using the pseudopotential plane wave method based on density functional theory with the local density approximation functional, pressure dependence of the structural, elastic and thermodynamic properties of the BeP2N4 compound was investigated. Calculated lattice parameters, structural stability and phase transition pressure of both polymorphs of BeP2N4, namely phenakite and spinel phases, are in good agreement with available data. Pressure dependence of the single-crystal and polycrystalline elastic moduli and their related properties were calculated and discussed. Thermal conductivity minimums for both BeP2N4 polymorphs were estimated through Clarke's and Cahill's models. Elastic anisotropy was analyzed for both considered polymorphs. Pressure and temperature dependences of some macroscopic thermodynamic parameters were computed for both phases of the title compound. (C) 2019 Elsevier B.V. All rights reserved.