Vibrational excitation of the N₂⁺first negative (0,0), (1,0) and (2,0) bands by electron impact: a theoretical study using the<i>R</i>-matrix approach

Abstract

Ab initio cross section calculations for vibronic excitation using the R-matrix approach have been performed on the N2+ molecular ion complex. A three-state close-coupling expansion is used where the electronic target states; X 2g+, A 2u and B 2u+ of the molecular cation are represented by a valence configuration-interaction approximation. A non-adiabatic approximation is invoked to study vibronic excitation for the first three negative bands, (0,0), (1,0) and (2,0) of the X-B transition (B 2u+v´X 2g+v´´) of N2+. Fixed-nuclei and non-adiabatic cross section results are compared with the available experimental data for the (0,0) band and the breakdown of the adiabatic fixed-nuclei approximation is clearly evident for the vibronic excitation of the (1,0) and (2,0) bands in this molecular ion complex.