Spectroscopic constants of the Kolos-Wolniewicz potential for H 2

Abstract

Recently Kolos and Wolniewicz used an 80-term electronic wave function in an accurate variational calculation of the H 2 ground-state potential. For this potential the coefficients in power series expansions about the minimum are here determined. The expansions are carried out only in restricted subdomains of internuclear separation; the potential coefficients are thereby found not to vary significantly as the number of terms included in the series varies. (Without subdomain restriction, calculations of this type generally have led to coefficients that vary widely.) Resulting Dunham potential coefficients a 0, a 1, a 2, a 3, and a 4 are 0.7971 × 10 5 cm −1, −1.600, 1.86, −2.1 and 2.3, respectively. From these the spectroscopic constants are found to be Y 10 = +4402, Y 20 = −122, Y 01 = +60.82, Y 11 = −3.03, Y 02 = −0.0465, Y 12 = +0.0016, and Y 03 = +4.98 × 10 −5, all in cm −1. When account is taken of computer precision limitations in the Kolos-Wolniewicz calculation, only Y 01 and Y 11 appear to differ significantly from experimental values.