Long-range interactions between two2sexcited hydrogen atoms

This is the authors' abstract. We don't add key points for this paper.

The doubly excited ¹Σg⁺ and ³Σᵤ⁺ states of the H₂ molecule converging to the H(n=2)+H(n^'=2) limit have been calculated using explicitly correlated basis functions, giving accurate results out to a nuclear separation sufficiently large to apply asymptotic expansions for the potential energy. The autoionization widths have been obtained using the complex-scaling method. For nuclear separations larger than 22 a.u., asymptotic expressions for the interaction energies have been obtained from perturbation theory.