Dissociation energies of He2+(X2Îu+) and He2(A 1Îu+)

The configuration-interaction method is applied to calculate the dissociation energy of He2+(X2Îu+), yielding a rigorous lower bound of 2.454 eV and a best value of 2.469 ±0.006 eV. These results are used, in combination with available spectroscopic data on vibrational states of the A 1Îu+ state of He2, to unequivocally make an assignment of 2.549±0.012 eV for the apparent dissociation energy and to predict a barrier height of 0.080±0.018 eV for this state. © 1971 The American Physical Society.