Car–Parrinello Molecular Dynamics + Metadynamics Study of High-Temperature Methanol Oxidation Reactions Using Generic Collective Variables

We used Car–Parrinello molecular dynamics (CPMD) and metadynamics in conjunction with the recently introduced social permutation invariant collective coordinates to study the mechanism of high-temperature methanol oxidation. Using a set of biased MD trajectories, we collected specific elementary reactions that arise during the simulations and assembled their connectivity in a small reaction network. A subset of the reaction network generated with metadynamics is compared to a consensus reaction network generated from many literature sources, and the many similarities indicate that this approach may be a useful way to enumerate bimolecular radical reactions in complex systems. We also demonstrated some intrinsic similarities to atomic contact maps used in our metadynamics approach and the reaction matrix/operators that are found in common mechanism generation algorithms. Extending the capabilities of these new generic collective variables for the study of complex reaction networks can help overcome limitations of enhanced sampling methods in the study of chemical reactions.