First-principles studies of the structural, elastic, vibrational, and thermodynamic properties of nonlinear chalcogenide LiGaTe2 under pressure

First-principles calculations for the structural, elastic, thermal and vibrational properties of LiGaTe2 under pressure up to 5GPa have been systematically investigated within the framework of the density functional theory. The lattices parameters found a, c and the bulk modulus B under zero pressure and zero temperature are close with the experimental data and the theoretical results. The analysis of the mechanical constants and the frequencies of the phonons found, confirms that the compound LiGaTe2 is dynamically and mechanically stable up to 5GPa. The effect of pressure on elastic constants Cij, bulk modulus B, Young's modulus E, Poisson ratio ν, shear modulus G, and compressibility k of LiGaTe2 are also successfully obtained and discussed. In addition, the thermal properties of LiGaTe2, such the heat capacity CV and Cp, the grüneisen parameter γ and the thermal expansion coefficient α are predicted by the quasi-harmonic approximation (QHA).