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ABSTRACT Cross-sections and rate coefficients for rovibronic excitation of the CH+ ion by electron impact and dissociative recombination of CH+ with electrons are evaluated using a theoretical approach combining an R-matrix method and molecular quantum defect theory. The method has been developed and tested, comparing the theoretical results with the data from the recent Cryogenic Storage Ring experiment. The obtained cross-sections and rate coefficients evaluated for temperatures from 1 to 10 000 K could be used for plasma modelling in the interpretation of astrophysical observations and also in the technological applications where the molecular hydrocarbon plasma is present. 

This study presents Born–Oppenheimer energies and transition dipole moments of the 36 lowest electronic states of the N2+ ion as a function of internuclear distance in the interval between 1.5 and 10 bohrs obtained in first-principles calculations. The electronic states are of the total electronic spin S = 1/2, 3/2, and 5/2, dissociating toward to the lowest four N(4S0) + N+(3P), N(2P0) + N+(3P), N(2D0) + N+(3P), and N(4S0) + N+(1D) dissociation limits. Energies of the lowest states, dissociating toward to the N(4S0) + N+(3P) limit, are computed accounting for relativistic corrections. The obtained potential energy curves and the transition dipole moments are employed to compute vibrational energies in these states, vibronic transition dipole moments, and the Einstein coefficients for radiative transitions between the vibronic levels. 

Energies, wavefunctions and lifetimes of vibrational resonances were computed for 18O-enriched isotopologue 50O_3=16O16O18O and 16O18O16O of the ozone molecule using hyperspherical coordinates and the method employing complex absorbing potential. 

This article presents a method of computing bound state potential curves and autoionizing curves using fixed-nuclei R-matrix data extracted from the Quantemol-N software suite. It is a method based on two related multichannel quantum-defect theory approaches. One is applying bound-state boundary conditions to closed-channel asymptotic solution matrices, and the other is searching for resonance positions via eigenphase shift analysis. We apply the method to the CH molecule to produce dense potential-curve datasets presented as graphs and supplied as tables in the publication supplement. 

Electron collision cross section data are complied from the literature for electron collisions with the nitrogen molecules, N2, N2+, and N2*. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, rotational excitation, vibrational excitation, electronic excitation, dissociative processes, and ionization. The literature has been surveyed up to the end of 2021. For each of these processes, the recommended values of the cross sections are presented. 

Abstract We discuss peculiar features of electron scattering on the N 2 molecule and the N 2 + ion, that are important for modeling plasmas, Earth’s and other planets’ atmospheres. These features are, among others: the resonant enhancement of the vibrational excitation in the region of the shape resonance around 2.4 eV, the resonant character of some of electronic excitation channels (and high values of these cross sections, both for triplet and singlet states), high cross section for the dissociation into neutrals, high cross sections for elastic scattering (and electronic transitions) on metastable states. For the N 2 + ion we discuss both dissociation and the dissociative ionization, leading to the formation of atoms in excited states, and dissociative recombination which depends strongly on the initial vibrational state of the ion. We conclude that the theory became an indispensable completion of experiments, predicting many of partial cross sections and their physical features. We hope that the data presented will serve to improve models of nitrogen plasmas and atmospheres. Graphical abstract