Some doubly excited states of He22+

Abstract

Ab initio potential energy curves have been determined in the following range of internuclear distances R:1.02²⁺ having the 2p sigma _u wavefunction of the ion He₂³⁺ as the core orbital. To the best of the authors' knowledge, results for these states have not appeared previously in the literature. The calculations have been performed through first-order perturbation theory using as zero-order wavefunction an explicitly correlated prolate spheroidal function containing no adjustable parameters.