Low-energy electron impact dissociative recombination and vibrational transitions of N₂⁺

Cross sections and thermal rate coefficients are computed for electron-impact dissociative recombination and vibrational excitation/de-excitation of the N+2 molecular ion in its lowest six vibrational levels, for collision energies/temperatures up to 2.3 eV/5000 K

Dissociative recombination of N2_2H+^+: A revisited study

Dissociative recombination of N$_2$H$^+$ is explored in a two-step theoretical study. In a first step, a diatomic (1D) rough model with frozen NN bond and frozen angles is adopted, in the framework of the multichannel quantum defect theory (MQDT). The importance of the indirect mechanism and of the bending mode is revealed, in spite of the disagreement between our cross section and the experimental one. In a second step, we use our recently elaborated 3D approach based on the normal mode approximation combined with R-matrix theory and MQDT. This approach results in satisfactory agreement with storage-ring measurements, significantly better at very low energy than the former calculations.Comment: 9 pages, 5 figures, 1 tabl

Theoretical study of ArH+ dissociative recombination and electron-impact vibrational excitation

Cross-sections are presented for dissociative recombination and electron-impact vibrational excitation of the ArH+ molecular ion at electron energies appropriate for the interstellar environment. The R-matrix method is employed to determine the molecular structure data, i.e. the position and width of the resonance states. The cross-sections and the corresponding Maxwellian rate coefficients are computed using a method based on the Multichannel Quantum Defect Theory. The main result of the paper is the very low dissociative recombination rate found at temperatures below 1000K. This is in agreement with the previous upper limit measurement in merged beams and offers a realistic explanation for the presence of ArH+ in exotic interstellar conditions