Communication: An accurate global potential energy surface for the OH plus CO → H + CO2 reaction using neural networks

We report a new global potential energy surface of the HOCO system based on the F12 correction of unrestricted coupled-cluster with singles doubles and approximative triples using the augmented correlation-consistent polarized valence triple-zeta basis set (UCCSD(T)-F12/AVTZ), fitted by using the neural networks. Quantum dynamics calculations confirmed the satisfactory convergence of surface with respect to the number of data points and fitting process. It is found that the total reaction probabilities and complex-formation probabilities obtained on the present surface differ considerably with those obtained on the potential energy surface recently reported by Li et al. [J. Chem. Phys. 136, 041103 (2012)]. Various comparisons revealed that the present surface is substantially more accurate than that surface, representing the best available potential energy surface for this benchmark complex-forming four-atom system. (C) 2013 AIP Publishing LLC.