Dickinson Energy of H2+

Abstract

Dickinson's function for H₂⁺ is recalculated for the ${\text{1sσ}}_g$ and ${\text{2pσ}}_u$ states at nuclear separations up to 20 a.u. Although inadequate near the ground‐state minimum, the Dickinson function is very good for larger separations, and describes quite accurately the shallow potential minimum ${\mathrm{(D}}_e\text{\hspace{0.17em}≈\hspace{0.17em}0.015}\mathrm{eV}{\mathrm{,\; R}}_e\text{\hspace{0.17em}≈\hspace{0.17em}12.6}\mathrm{a.u.})$ in the “repulsive” ${\text{2pσ}}_u$ excited state.