Accurate potential surfaces for the first three lowest states of reaction O(3P) + C2(a3Πu) → CO(X1Σ) + C(1D)

The higher level ab initio methods are performed to reduce an accuracy of three-dimensional adiabatic potential energies. And the accurate numerically fitted method, 3D-spline method, is used to get an accuracy adiabatic potential energy surfaces for the three lowest states of CCO molecule. Starting from reactants, the title reaction through the first two lowest states have no reaction barrier should be very fast. The title reaction pathways should be different depending on the angles that the oxygen atom O(P-3) attacked the C-2(a(3)Pi(u)) molecule. If the angles less than 60 degrees, the reaction pathway should be O(P-3) + C-2((3)Pi(u)) -> CCO(C-infinity) -> CO(X-1 Sigma) + C(D-1); On the other hand, if the angles great than 65 degrees the transition state should be take into account, the reaction pathway is (OP)-P-3) + C-2((3)Pi(u)) -> CCO(C-2v) -> TS -> CCO(C-infinity) -> CO(X-1 Sigma) + C(D-1).