Adiabatic and strictly diabatic potential curves of He2+2

Abstract

Adiabatic and strictly diabatic potential curves were calculated for the two lowest electronic states of He22+. The diabatization procedure leads to a repulsive diabatic curve dissociating to He+ + He+ and a bound curve dissociating to He2+ + He, crossing at the internuclear distance of 1.55 bohr. The diabatic bound state has dissociation energy of 3.15 eV. The existence of a metastable potential well in the (adiabatic) X1Σg+ state of He22+ can be interpreted in terms of a strong interaction between the diabatic curves.