15min:

P. R. BUNKER, Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada; R. E. MOSS, Department of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K..

Previous studies of the g/u electronic symmetry breaking interaction between the rotation-vibration levels of the X ² _g⁺ ground electronic state and the A ² _u⁺ first excited electronic state of H₂⁺ have focused on explaining the large hyperfine structure observed in some rovibronic transitions between these electronic states^,. The interaction is an ortho-para interaction between levels of the two electronic states. It gives rise to an interesting new electric dipole spectrum that consists of forbidden rotation and rotation-vibration transitions within the X ² _g⁺ ground state involving levels that are near the dissociation limit. Such a spectrum will occur for any homonuclear diatomic ion having nuclei with non-zero spin such as ³He₂⁺, Li₂⁺ and ²¹Ne₂⁺.