Elastic constants and interatomic bond force constants of A-=SUP=-II-=/SUP=-B-=SUP=-III-=/SUP=--=SUB=-2-=/SUB=-C-=SUP=-VI-=/SUP=--=SUB=-4-=/SUB=- compounds

Abstract

The density functional theory (DFT) was used to calculate the elastic constants cij of CdGa2S4, CdGa2Se4, CdGa2Te4, and ZnGa2Se4 thiogallates. The values of B bulk modulus of elasticity have been calculated. The regularities in the dependences of the optical phonons frequencies on the masses of atoms of compounds are established. The force constants of interatomic bonds in CdGa2Te4 and ZnGa2Se4 compounds have been determined. Keywords: elastic constants, force constants, phonons, raman scattering, tetragonal syngony, reduced mass, chalcopyrites.