THEORETICAL VIBRATIONAL ENERGY LEVELS OF $H_{2}$ ASSOCIATED WITH VARIOUS LC STO MO CONFIGURATION COMBINATIONS

Abstract

Vibrational energy level $G_{v}$ and first differences $\Delta G_{y}$ have been determined for eleven different theoretical potential curves of the $H_{2}$ ground electronic state. These potential curves- were previously determined by McLean, Weiss, and $Yoshinline^{1}$ using LC STO MO wave functions with configuration interaction. Values of $G_{v}$ and $\Delta G_{v}$ have been calculated for each potential curve the use of the WBK approximation. Since each wave function differs from the proceeding one by the addition of one more configuration, a comparison of the $\Delta G_{v}$ curves provides a measure of the influence of each configuration on the shape of the $\Delta G_{v}$, curve. The effects of each configuration on the vibrational levels will be discussed. The $\Delta G_{v}$ curves group into two distinct families. All wave functions which include the $(\sigma_{u} lS \sigma lS^{\prime})$ configuration have rapidly converging vibrational levels at high quantum number v, characteristic of the experimental levels. Those wave functions which exclude $(\sigma_{u} lS \sigma lS^{\prime})$ show $\Delta G_{v}$, curves which have a positive curvature at all values of v for which calculations have been made.