Resonances in low-energy electron scattering fromHCNH+

Abstract

The energies and autoionization widths of resonances in the collision of low-energy electrons from $\mathrm{H}\mathrm{C}\mathrm{N}{\mathrm{H}}^{+}$ involved in dissociative recombination have been derived from electron-scattering calculations using the complex Kohn variational method. No low-lying resonance state that crosses the ground state of $\mathrm{H}\mathrm{C}\mathrm{N}{\mathrm{H}}^{+}$ in the Franck-Condon region was found. One state, having predominantly valence character, was found to lie close in energy to the $\mathrm{H}\mathrm{C}\mathrm{N}{\mathrm{H}}^{+}$ ion ground state, but remained below the ion ground state for all geometries. The presence of avoided crossings between the resonance states is described and the effects of these crossings on the properties of the resonances are discussed. When C-H and N-H bonds are stretched, there is no significant difference in the shape of the potential-energy surfaces.