Dissociative recombination of NO+: calculations and comparison with experiment

Multichannel quantum defect calculations for NO+ dissociative recombination (DR) for electron energies from threshold to 8 eV are presented. The calcu lations use electronic energies and autoionization widths of valence states obtained from ab initio R-matrix calculations with the corresponding poten tial curves calibrated using available spectroscopic data. Six valence stat es open to dissociation are included in the final calculations. Excellent a greement with the measured cross sections is obtained for the low-energy DR , up to 3 eV and, for the first time, the peak observed in the cross sectio n at high energy is accounted for. The importance of the various dissociati ve states at different electron energies, as well as the direct and indirec t processes, is discussed. Compared to previous theoretical studies, the in clusion of a third dissociative state of (2)Pi symmetry and the larger auto ionization width of the B' (2)Delta state are found to be particularly impo rtant for the agreement with experiment.