Analytical Potential Energy Curves of Inverse Polynomial Form for Diatomic Molecules: An Application of Two-Step Method to Li2, Na2, NaK, and K2 Molecules

Horng-Tay Jeng；Chen-Shiung Hsue

Chinese Journal of Physics

34卷5期（1996 / 10 / 01）

1237 - 1253

英文

We apply the recently introduced two-step method to the lowest triplet electronic states of the diatomic molecules Li2, Na2, NaK, and K2. The analytical potential energy curves of these states are constructed in the form of inverse polynomial with the experimental vibrational energies as the only inputs. The dissociation energies and the equilibrium constants are also determined. The forms of the interatomic potentials have correct asymptotic behavior in both the short range limit and the long range limit. In contrast to the situations in the widely-used RKR method and also the Dunham type potentials, none of the unphysical inner and outer walls appears in our interatomic potential curves. Based on the potentials obtained, it is predicted that additional unobserved higher vibrational bound states exist for all the systems considered here. This is to be compared with the fact that both the RKR method and the Dunham type potentials have so far failed to predict the existence of the additional bound states for these systems. The described treatments can be applied to other systems as well.