A four-parameters model for molar entropy calculation of diatomic molecules via shifted Tietz-Wei potential

We present an accurate and a new closed-form representation for the molar entropy of gaseous diatomic molecule substances. The predicted molar entropy is in excellent agreement with experimental data in a wide range of temperature for CsO, CsF and CsCl molecules. The average relative deviation of the obtained values from experimental data are 0.272%, 0.359% and 0.361% for CsO, CsF and CsCl molecules, respectively. The present model needs only to know the experimental values of four parameters which are dissociation energy, equilibrium vibrational frequency, equilibrium bond length, and the reduced molecular mass.