The 2p interloper resonances in collisions

Ab initio electron scattering calculations using the R-matrix approach have been performed for within a three-state valence configuration-interaction model (VCI). The lowest three electronic target states (, and the ) of this molecular nitrogen cation are included in the close-coupling method, with each state being represented by a valence CI approximation. From a detailed analysis of the resonance structure found in our work for the symmetries we find four prominent Rydberg series of the type , , , and a interloper resonance. This interloper molecular resonance associated with the B state of is seen to cause distortions of the resulting resonance spectra. A comparison of our total cross sections for the X - B transition shows excellent agreement with the available experimental data.