The modified Pitzerndash;Gwinn method for partition function of restricted internal rotation of a molecule

摘要

The Pitzerndash;Gwinn method is modified with the Wignerndash;Kirkwood perturbation expansion used instead of the classical partition function. This method is applied to the calculation of partition function of restricted internal rotation for various temperatures and potential barriers. Numerical results show that the modified Pitzerndash;Gwinn method provides remarkably accurate partition function.