Ab initio studies of structural, elastic and thermal properties of copper indium dichalcogenides (CuInX2: XÂ =Â S, Se, Te)

We have performed ab initio calculations for the structural, elastic and thermal properties of the copper indium dichalcogenides (CuInX2: X = S, Se, Te). We have used the full potential linearized augmented plane wave (FP-LAPW) method to find the equilibrium structural parameters and to compute the full elastic tensors. The thermodynamical properties such as thermal expansion, heat capacity, Debye temperature, entropy, Grüneisen parameter and bulk modulus were evaluated employing the quasi-harmonic Debye model at different temperatures (0-700 K) and pressures (0-8 GPa) and the silent results were interpreted. Based on the semi-empirical relation, we determined the hardness of the materials, which attributed to different covalent bonding strengths. Most of the investigated parameters are not reported by previous researchers.