Resonant ion-pair formation in electron collisions with $\mathrmHD^+$ and $\mathrmOH^+$

Resonant ion-pair formation from collisions of electrons with electronic and vibronic ground-state diatomic molecular ions has been studied in the present work for HD+ and OH+. The cross section for HD+ has a magnitude of the order of 3×10-19 cm2 and is characterized by an energy threshold and 14 resolved peaks in the energy range up to 16 eV. A theoretical study confirms that the structures derive primarily from quantum interference of the multiple dissociation pathways. Measurements for OH+ reveal that the cross section for H+ and O- formation is lower than 10-21 cm2 at energies of 6 and 12 eV.