Dissociation energy of diatomic molecules

The dissociation energy of twelve diatomic molecules has been determined by fitting four-parameter potential function U(r) = D-e[[1 - exp(-b(r - r(e))}]/[1 - C exp(-b(r - r(e))]](2) to the true Rydberg-Klein-Rees (RKR) curves for their fifteen electronic states using the mean square deviation as the criterion for the selection of the best fit. Average deviation of D-e has been found to be 2.7% as compared to 20.5% obtained with Lippincott's potential function for these molecules. In addition the anharmonocity constant omega(e)x(e) has also been calculated for the same electronic states yielding average mean deviation 8.9%.