Ab initio calculations of autoionizing states using block diagonalization: Collinear diabatic states for dissociative recombination of electrons with N2H+

Dissociating autoionizing states for dissociative recombination of electrons with N2H+ have been calculated using block diagonalization. Multi-reference CI calculations for collinear N2H and N2H+ were performed to assess the branching ratio to the product channels. The effects of the strong Rydberg-valence mixing in the N2H excited states were disentangled from the changes in the molecular orbitals arising solely from N-2 bond stretching and breaking. The results suggest that N-2 + H should be favored over NH + N, because of the absence of a favorable dissociating state for the N-2 bond breaking. (C) 2012 Elsevier B. V. All rights reserved.