Dissociation Energy ofHe2+(Σu2+)

Abstract

The potential curve for ${{\mathrm{He}}_2}^{+}\left({{}_{}{}^2{}_{}{}^{}\Sigma _u^{}{}_{}{}^{}}^{+}\right)$ has been calculated using Slater-type orbitals as a basis for a 26-term atomic orbital-configuration wave function. The calculation establishes a rigorous lower bound, $E_{\exp }\left(\mathrm{atoms}\right)-E_{\mathrm{calc}}\left(\mathrm{molecule}\right)$, of 2.24 eV for the dissociation energy of ${{\mathrm{He}}_2}^{+}\left({{}_{}{}^2{}_{}{}^{}\Sigma _u^{}{}_{}{}^{}}^{+}\right)$. This value together with the ionization energies of ${\mathrm{He}}^{*}\left(2\mathrm{}{}_{}{}^3{}_{}{}^{}S\right)$ and ${{\mathrm{He}}_2}^{*}\left({{}_{}{}^3{}_{}{}^{}\Sigma _u^{}{}_{}{}^{}}^{+}\right)$ is used in an energy cycle to give a lower limit of 1.76 eV for the dissociation energy of ${{\mathrm{He}}_2}^{*}\left({{}_{}{}^3{}_{}{}^{}\Sigma _u^{}{}_{}{}^{}}^{+}\right)$.