Abstract: The reaction of Y+ with CS2, which was selected as the representative system of the reactions of second-row transition metal ions with CS2, was investigated using density functional theory (DFT) with the Stuttgart pseudo potentials and corresponding basis sets for Y+ and the standard 6-311+G(2d) basis sets for C and S atoms. Single-point UCCSD(T) energy calculations were carried out for each stationary point. The object of this investigation was the elucidation of the reaction mechanism. The result shows that the reaction mechanismbetween yttriumion and CS2 is an insertion-elimination mechanism. Intersystemcrossing may occur in the reaction of Y+ with CS2 and a minimumenergy crossing point has been found. All theoretical results are in line with early experiments.

Key words: Potential energy surface, Reaction mechanism, Minimumenergy crossing point