An accurate analytical formula for the van der Waals potentials of homonuclear rare-gas dimers with one adjustable parameter

摘要

In the present article, the Tang-Toennies-Yiu (TTY) potential model is modified by introducing one adjustable parameter. Then, the van der Waals potentials of He-2, Ne-2, Ar-2, Kr-2, and Xe-2 are calculated by this model with the adjustable parameter being determined by the well determined well depth D-e of these systems. Based on the derived potentials, the vibrational energy spacings of these systems are also calculated. It is shown that the present derived potentials and vibrational energy spacings agree well with experiment and other theoretical calculations. Finally, the normalization constant A in the asymptotic wave function of rare-gas atoms is estimated. The present derived normalization constant A is very close to the one by calculating the ratio between the Hartree-Fock function and the asymptotic wave function. The results confirm that absorbing the first-order polarization energy into the exchange energy expression is a well approximation for the present systems.