Thermodynamic Properties of CdSe Crystals Using First Principles Calculations and Experiment

Abstract

The cluster models have been built for calculation of the geometric and thermodynamic parameters based on the analysis of the crystal and electronic structure of CdSe crystals in the cubic phase. The temperature dependence of formation energy ΔE, formation enthalpy ΔH, Gibbs free energy ΔG, entropy ΔS, specific heat capacity at constant volume C V and constant pressure C P have been defined according to first-principles calculations. Computer calculations of thermodynamic parameters carried out by density functional theory (DFT) and with using the hybrid B3LYP valence base set. Also, in the work have been derived analytical expressions of temperature dependences of the presented thermodynamic parameters, which have been approximated by the first-principles calculation data using mathematical package Maple 14. Theoretically calculated data of specific heat at constant pressure CP compared with the data of calorimetric measurements.