Improved theoretical dissociation energy and ionization potential for the ground state of the hydrogen molecule

Abstract

A new 155‐term electronic wave function for the ground state of the hydrogen molecule has been selected which gives a more accurate Born–Oppenheimer potential energy curve in the range 3.2≤R≤7.2 bohr. The largest improvement 0.112 cm−1 has been found for R=4.8 bohr. The adiabatic corrections have also been calculated in the full range of R giving more accurate values. These new results have been employed to calculate the dissociation energies and ionization potentials for H2, HD, and D2. The agreement between resulting dissociation energies and recently published experimental data are excellent; the discrepancy is within the experimental error limits. For the ionization potential the agreement is fairly good, although not ideal. There is still room for improvement from both theoretical and experimental side.