Dissociative recombination of NO⁺: calculations and comparison with experiment

Abstract

Multichannel quantum defect calculations for NO + dissociative recombination (DR) for electron energies from threshold to 8 eV are presented. The calculations use electronic energies and autoionization widths of valence states obtained from ab initio R-matrix calculations with the corresponding potential curves calibrated using available spectroscopic data. Six valence states open to dissociation are included in the final calculations. Excellent agreement with the measured cross sections is obtained for the low-energy DR, up to 3 eV and, for the first time, the peak observed in the cross section at high energy is accounted for. The importance of the various dissociative states at different electron energies, as well as the direct and indirect processes, is discussed. Compared to previous theoretical studies, the inclusion of a third dissociative state of 2 symmetry and the larger autoionization width of the B 2 state are found to be particularly important for the agreement with experiment.

The dissociative recombination of fluorocarbon ions III: CF+2and CF+3

“…The origin of the resonant structure, however, is thought to be due to electron recombination into Rydberg states converging to excited states of the ion; these states are often repulsive in nature and hence dissociate directly. High energy peaks in recombination cross sections have been seen in a number of theoretical calculations [24][25][26][27][28], and such a feature was seen in our recent measurement of CF' [3]. The structure at around 1 eV in the CF13 data is not statistically significant, and therefore it is not possible to draw any conclusions concerning that.…”

Uncertainty estimates for theoretical atomic and molecular data

“…The cross sections for these dissociative processes are very sensitive to the locations of curve crossings between the dissociative resonance state(s) and the target curve; the resulting cross sections are known to be highly sensitive to this aspect of the calculation [82,[125][126][127][128].…”

Reactive collisions between electrons and NO+ions: rate coefficient computations and relevance for the air plasma kinetics

“…In a previous paper (Schneider et al 2000a), hereafter referred to as Paper I, ab initio potential curves have been calibrated from Raoult (1987) and couplings have been derived from the autoionization widths of Rabadán and Tennyson (1997) to perform a series of MQDT calculations of the dissociative recombination cross section of NO + , assuming the molecular ion to be in its ground state (…”

“…The purpose of the present work is to use the above described data set (Schneider et al 2000a) to provide a wide range of rate coefficients for reactive collisions between NO + ions and low-energy electrons, involving not only dissociative recombination and inelastic collisions, but also elastic and superelastic collisions which, to our knowledge, have not been the object of theoretical investigations for this molecular ion. This study aims to investigate the dependence of the rate coefficients on the initial vibrational level of the target and, as well, to provide data necessary to develop a kinetic model of air plasmas (Bultel et al 2005).…”