Ab initio treatment of charge transfer in CS+ molecular system

The charge transfer process C+(2s22p)2P + S(3s23p4)3P → C(2s22p2)3P + S+(3s23p3)4S is important in the modellisation of the interstellar medium chemistry. The rate constant generally used in the astrochemical models for the C+ + S → C + S+ reaction is 1.5 × 10−9 cm3 s−1 [1] between 10 K and 41 000 K, but it remains uncertain for such a large domain of temperature. Since no precise calculation has been ever performed for this process, we have undertaken the first complete ab initio molecular treatment of this collision, followed by a semi-classical dynamics. The results suggest that the rate constant adopted in astrochemical models might be overestimated.