Accurate Prediction of Thermodynamic Functions of H2 and LiH Using Theoretical Calculations

Abstract

Thermodynamic functions of two diatomic molecules gas, H2 and LiH, from theoretical point of view were predicted. The Schrodinger equation was analytically solved with the generalized Morse potential using Nikiforov–Uvarov method. The energy eigenvalues were obtained for the two cases (i) constant effective mass and (ii) position-dependent effective mass. The partition function of two diatomic molecules gases H2 and LiH was analytically obtained. Thermodynamic functions of the gases such as specific heat in constant pressure and volume, entropy, and enthalpy were determined and compared with experimental data. We could find an interesting point from our theoretical calculations. The results indicated that the calculated thermodynamic functions are in agreement with experimental data when the generalized Morse potential with variable mass was considered. This means that one can obtain best theoretical results by setting variable mass parameters.