New Born–Oppenheimer potential energy curve and vibrational energies for the electronic ground state of the hydrogen molecule

Abstract

The Born–Oppenheimer potential energy curve for the electronic ground state of the hydrogen molecule has been computed for internuclear distances 0.2≤R≤12.0 bohr. At all R the energies are lower than any previously reported values. At the equilibrium distance the improvement is negligible; its largest value, 0.47 cm−1, has been obtained for R=2.4 bohr. Vibrational energies have been computed for all isotopic species using the new potential energy curve. For H2, HD, and D2 the recent nonadiabatic corrections of Wolniewicz have been included. The resulting dissociation energies of H2 and HD agree with the experimental values within the experimental error limits; for D2 the discrepancy amounts to 0.6±0.3 cm−1.