Accurate Born-Oppenheimer potentials for excited $Σ^{+}$ states of the hydrogen molecule

Abstract

We report on highly accurate calculations of Born-Oppenheimer potentials for excited n Σ + states of the hydrogen molecule for all possible combinations of singlet/triplet and gerade/ungerade symmetries up to n = 7. A relative accuracy of 10 −10 (0.00002 cm −1 ) or better is achieved for all the internuclear distances and all the excited states under considerationan improvement with respect to the best results available in the literature by at least 6 orders of magnitude. Presented variational calculations rely on efficient evaluation of molecular integrals with the explicitly correlated exponential basis in arbitrary precision arithmetics.

Shape resonances in H$_2$ as photolysis reaction intermediates

“…F0-level energies were obtained by solving the Schrödinger equation using Born-Oppenheimer [38], adiabatic [39] and relativistic [40] potential energy curves, while including leading-order radiative corrections taken from Ref. [41] for the hydrogen molecular ion and esti- mating the effects of nonadiabaticity based on Ref.…”