Rate constant calculations for atom-diatom reaction involving an open shell atom and a molecule in a Π electronic state at very low temperature

We present a short study of the influence of the open shell nature of the reactants on the kinetics of the title type of reactions. We consider one coupling scheme of the different angular momenta of the reactants to calculate the matrix elements of the intermolecular potential. In the limit of zero temperature, this potential is used within a perturbative approach to obtain analytical formulae for the rate constants as a function of temperature for several types of open shell atom-diatom reactions. Various examples including the C(X 3P0) + NO(X 2Π1/2), C(X 3P0) + SH(X 2Π3/2), O(X 3P2) + CH(X 2Π1/2) and O(X 3P2) + OH(X 2Π3/2) reactions are used to propose an analysis of the role played by each contribution to the intermolecular potential for these reactions.