Energy spectral and theoretical prediction of molar entropy and molar Gibbs free energy for four diatomic molecules

This study combined a hyperbolic-type potential (HTP) and Pὃschl-Teller potential (PTP) as the studying potential. In a closed and compact form, the energy levels and the wave function of this non-molecular potential are calculated. The non-molecular parameters of the HTP plus PTP ( V 0 , V 1 , and V 2 ) are transformed to molecular constants and the outcome was used to study four molecules and molar thermodynamic properties such as entropy and Gibbs free energy of HF, BF, P 2 , and K 2 . Numerical values are obtained within a temperature range of 0 to 6000 K and pressure of 1 bar for the four diatomic molecules and compared with the standard results obtained from National Institute of Standards and Technology (NIST) database. The analytic prediction of the thermal properties of the four diatomic molecules shows excellent agreement with the standard result raising very small absolute average percentage deviation (AAPD) for all the molecules. This study shows that the potential is a perfect model to study both molecular and non-molecular systems.