Entropy and Gibbs free energy equations for the specialized Poschl-Teller potential

In this paper, the specialized Poschl-Teller potential is used to fit the internal vibration of a diatomic molecule. Analytical expression of partition function obtained for the system is used to derive equations of molar entropy and Gibbs free energy. The equations were used to study the thermodynamic properties of the ground states: F-2,F- HI, I-2, and KH diatomic molecules. Average absolute deviations of 0.3400%, 0.1619%, 0.5561%, and 0.3533% were obtained using the expression of molar entropy. The formula of reduced Gibbs free energy gave average absolute deviation of 0.1011%, 0.4355%, 0.2619%, and 0.2701% from the experimental data. The obtained results are in near total agreement with existing literature data on the examined diatomic molecules.