Pressure dependence of mechanical properties of perovskite-type hydride NaBeH₃ material: first principle calculations

First principle calculations of the elastic constants of perovskite-type hydride NaBeH₃ material have been accomplished using the density functional theory (DFT) within the local density approximation (LDA) and the pseudopotential plane-wave method. The elastic constants were compared fairly well with those previously calculated. We have also calculated the dependence of the elastic constants on hydrostatic pressure from 0 up to 96.55 GPa. We have found that the elastic constants follow a quadratic law with respect to the pressure. In this study, the bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, acoustic wave speed and Debye temperature of cubic NaBeH₃ material are also determined as a function of pressure. Both the acoustic wave speed and the Debye temperature of NaBeH₃ material change monotonously and non-linearly with increasing the pressure from 0 up to 96.55 GPa.