Analytical potential energy surface for O + C₂H₂ system

Full-dimensional analytical potential energy surfaces (PESs) for the O(1P) + C2H2 and O(3P) + C2H2 reactions are presented. The PESs are constructed by fitting thousands of ab initio data points using permutationally invariant polynomials. Electronic structure data are obtained within the restricted coupled cluster theory with single and double excitations with perturbative triple corrections and correlation consistent basis set of triple-zeta with diffuse functions. Motivated by experiments, formation of DOCC and cyclic DCCO at collision energies of 2.5–4 eV is examined using quasi-classical trajectory dynamics on the triplet surface.