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

Ab initio cross section calculations for vibronic excitation using the R-ma trix approach have been performed on the N-2(+) molecular ion complex. A th ree-state close-coupling expansion is used where the electronic target stat es; X (2)Sigma(g)(+), A (2)Pi(u) and B (2)Sigma(u)(+) of the molecular cati on 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 transitio n (B (2)Sigma(u)(+) upsilon' <-- X (2)Sigma(g)(+) upsilon ") of N-2(+). Fix ed-nuclei and non-adiabatic cross section results are compared with the ava ilable experimental data for the (0, 0) band and the breakdown of the adiab atic fixed-nuclei approximation is clearly evident for the vibronic excitat ion of the (1, 0) and (2, 0) bands in this molecular ion complex.