Quantum-Mechanical Potential-Energy Curve for the Lowest 1Σ<i>u</i>+ State of He2

Abstract

The potential-energy curve of the lowest 1Σu+ state of He2 is computed in a valence bond scheme using a 17-term wavefunction of Slater orbitals. A maximum in the potential curve occurs at 5.22 a0 with a computed height of 0.153 eV. A rigorous upper bound of 0.364 eV is found for the potential maximum. The rationalized dissociation energy for the best wavefunction is 1.719 eV at Re=2.11 a0, and a rigorous lower bound on the dissociation energy is 1.508 eV.