Reaction sampling and reactivity prediction using the stochastic surface walking method

Abstract

The prediction of chemical reactivity and thus the design of new reaction systems are the key challenges in chemistry. Here, we develop an unbiased general-purpose reaction sampling method, the stochastic surface walking based reaction sampling (SSW-RS) method, and show that the new method is a promising solution for reactivity prediction of complex reaction systems. The SSW-RS method is capable of sampling both the configuration space of the reactant and the reaction space of pathways, owing to the combination of two recently developed theoretical methods, namely, the stochastic surface walking (SSW) method for potential energy surface (PES) exploration and the double-ended surface walking (DESW) method for building pathways. By integrating with first principles calculations, we show that the SSW-RS method can be applied to investigate the kinetics of complex organic reactions featuring many possible reaction channels and complex hydrogen-bonding networks, as demonstrated here using two examples, epoxypropane hydrolysis in aqueous solution and β-d-glucopyranose decomposition. Our results show that simultaneous sampling of the soft hydrogen-bonding conformations and the chemical reactions involving hard bond making/breaking can be achieved in the SSW-RS simulation, and the mechanism and kinetics can be predicted without a priori information on the system. Unexpected new chemistry for these reactions is revealed and discussed. In particular, despite many possible pathways for β-d-glucopyranose decomposition, the SSW-RS shows that only β-d-glucose and levoglucosan are kinetically preferred direct products and the 5- or 7-member ring products should be secondary products derived from β-d-glucose or levoglucosan. As a general tool for reactivity prediction, the SSW-RS opens a new route for the design of rational reactions.

Mechanism and microstructures in Ga2O3 pseudomartensitic solid phase transition

“…In our implementation, the SSW pathway sampling is fully automated and divided into three stages in simulation, namely, (i) pathway collection via extensive SSW global search; (ii) pathway screening via fast DESW pathway building; [32][33][34] (iii) lowest energy pathway determination via DESW TS search. The first stage is the most important and most time-consuming part, which generates all the likely pairs of generalized reaction coordinates linking different crystal phases.…”

LASP: Fast global potential energy surface exploration

“…By combining the SSW method with the DESW method, it is now possible to achieve the automatic reaction pathway sampling. SSW pathway sampling can therefore be considered as an extension of the SSW global structure search . They share the same global structure search module.…”

Artificial Force Induced Reaction (AFIR) Method for Exploring Quantum Chemical Potential Energy Surfaces

“…A systematic approach, which can explore important geometries automatically, needs to be developed 14–16. Although there have been considerable efforts in the development of such automated searching approaches,17–45 a comprehensive review of various existing methods is beyond the scope of this personal account. This account will focus on the artificial force induced reaction46–49 (AFIR) method, developed by ourselves and implemented in the GRRM (global reaction route mapping) program 50,51.…”