Enthalpy, Gibbs free energy and specific heat in constant pressure for diatomic molecules using improved deformed exponential-type potential (IDEP)

In this work, we have studied such thermal function of diatomic molecules like hydrogen dimer, carbon monoxide, nitrogen dimer and lithium hydride using improved deformed exponential-type potential (IDEP). To this end, the energy spectra of the IDEP are obtained applying Greene-Aldrich approximation and appropriate coordinate transformation within the framework of non-relativistic quantum mechanics. With calculated energy eigenstates, we have deduced the partition function and such thermodynamic functions like specific heat in constant pressure, enthalpy and Gibbs free energy by employing the Poisson summation formula. We have compared our results with experimental data, and there is a good agreement between them.