Recombination and excitation of molecular cations with electrons: Application to H 2 +, BeD⁺ and BeT⁺

Among the most relevant reactive elementary processes in cold ionized gases are the dissociative recombination, the ro-vibrational excitation, the ro-vibrational de-excitation and the dissociative excitation. Their detailed description is essential for modeling these environments. By using a stepwise version of the multichannel quantum defect theory, we provide cross sections and rate coefficients for electron-induced reactions on H+2, BeD+ and BeT+ relevant for the chemistry of the primordial Universe and interstellar medium and for fusion related molecular plasmas. Different reaction mechanisms are revised for the H+2 molecular cation, namely direct vs. indirect and rotational vs. non-rotational processes. A complete set of vibrationally resolved rate coefficients for reactive collisions of BeD+ and BeT+ cations below their dissociation limit are presented.