Structural and elastic properties of CaMg2 Laves phase by Y-parameter and Reuss-Voigt-Hill methods

Structural, mechanical properties of CaMg2 Laves phase are investigated by the first-principle calculations and then the homogenized moduli are calculated by both the classical Reuss-Voigt-Hill estimation and a so-called Y parameter. Above all, the optimized crystal parameters are in very good agreement with the experimental data reported. Besides, elastic constants Cij are calculated, thus the shear modulus, bulk modulus, Young's modulus, Poisson's ratio are calculated to compare with the relative data in references. Contrary to Hill approach, the Y parameter enables to investigate the anisotropic characteristics and isotropic elastic properties of CaMg2 structure. By using Y parameter, we can see that Young's modulus and Poisson's ratio as a function of the compliance coefficient Sij (or elastic constants Cij) and plane orientation are distributed within a reasonable range, which are useful for the DFT study of similar hexagonal crystal structure at nanoscale.