The \(\textrm{He}^{+.}\) + \(\textrm{CH}_3\textrm{CN}\) Charge-Exchange Reaction: A Combined Semi-empirical and Quantum Chemical Study

The reaction with the \(\textrm{He}^{+.}\) cation is considered one of the most important processes in the destruction of interstellar complex organic molecules (iCOMs). The development of accurate astrochemical databases requires the detailed knowledge of the rate constants and branching ratios of the processes. The dynamics of the charge exchange process between \(\textrm{He}^{+.}\) and methyl cyanide ( \(\textrm{CH}_3\textrm{CN}\) ) can be studied through a Landau-Zener-Stückelberg approach, which needs a detailed analysis of the potential energy surface (PES). In the present contribution, the Improved Lennard-Jones (ILJ) formulation is used to unveil the main features of the PES for \(\textrm{He}^{+.}\) + \(\textrm{CH}_3\textrm{CN}\) reaction, in order to set the stage for an accurate investigation of the dynamics of the charge-exchange process. The low computational cost and the high portability of the ILJ formulation allows to extend the approach to the study of different systems, with relevance in several fields, ranging from astrochemistry to nanomaterials.