Dynamical and anisotropic behavior of the MSiP2 (MÂ =Â Be, Mg, Cd, Zn and Hg) compounds

Intensive calculations in the framework of the density functional theory (DFT) scheme have been carried out in order to predict accurately the elastic behavior and the equilibrium crystal parameters for the MSiP2 (M = Be, Mg, Cd, Zn and Hg) compounds. Emphasis is placed on the trends of the dynamical stability and anisotropic behavior related to elastic components. A rigorous analysis of linear compressibility in the chalcopyrite structures reveals their directional anisotropic behavior along the c-axis. As pressure is applied, the entitled compounds have shown polymorphic sequences from tetragonal, orthorhombic to metallic cubic structures. Also, we pay attention to the evolution of the tetragonal distortion which plays an important role in the change of the bonding nature through these phase transitions.