2017A&A...605A..22M

Aims. We aim to investigate fractionation reactions involved in the ¹²C/¹³C, ¹⁶O/¹⁸O, and ¹⁷O balance.
Methods. Full-dimensional rovibrational calculations were used to compute numerically exact rovibrational energies and thermal equilibrium conditions to derive the reaction rate coefficients. A nonlinear least-squares method was employed to represent the rate coefficients by analytic functions.
Results. New exothermicities are derived for 30 isotopic exchange reactions of HCO⁺ with CO. For each of the reactions, we provide the analytic three-parameter Arrhenius-Kooij formula for both the forward reaction and backward reaction rate coefficients, that can further be used in astrochemical kinetic models. Rotational constants derived here for the ¹⁷O containing forms of HCO⁺ may assist detection of these cations in outer space.