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.

Cross-sections for dissociative recombination and electron-impact vibrational excitation of the BF 2 + molecular ion are computed using a theoretical approach that combines the normal modes approximation for the vibrational states of the target ion and use of the UK R-matrix code to evaluate electron–ion scattering matrices for fixed geometries of the ion. Thermally-averaged rate coefficients are obtained from the cross-sections for temperatures in the 10–3000 K range.

We used the multichannel quantum defect theory to compute cross sections and rate coefficients for the dissociative recombination of CH ${}^{+}$ initially in its lowest vibrational level $v_i^{+}=0$ with electrons of incident energy below $0.2$ eV. We have focused on the contribution of the 2 ${}^2\Pi$ state which is the main dissociative recombination route at low collision energies. The final cross section is obtained by averaging the relevant initial rotational states $(N_i^{+}=0,\cdots ,10)$ with a 300 K Boltzmann distribution. The Maxwell isotropic rate coefficients for dissociative recombination are also calculated for different initial rotational states and for electronic temperatures up to a few hundred Kelvins. Our results are compared to storage-ring measurements.

The reactive collision of the CH ⁺ molecular ion with an electron is studied in the framework of the multichannel quantum defect theory, taking into account the contribution of the core-excited Rydberg states. In addition to the X ¹ Σ ⁺ ground state of the ion, we also consider the contribution to the dynamics of the a ³ Π and A ¹ Π excited states of CH ⁺ . Our results—in the case of the dissociative recombination in good agreement with the storage ring measurements—rely on decisive improvements—complete account of the ionisation channels and accurate evaluation of the reaction matrix—of a previously used model.