1RExpansion forH2+: Analyticity, Summability, Asymptotics, and Calculation of Exponentially Small Terms

Abstract
The 1R perturbation series for H2+ has a complex Borel sum whose imaginary part determines the asymptotics of the perturbed energy coefficients E(N). The full asymptotic expansion for the energy includes complex, exponentially small terms: {E(R)ΣE(N)(2R)N+,eRnΣa(N)(2R)N}{+e2Rn[Σd(N)(2R)N+logRterms]±ie2RnΣc(N)(2R)N+}