Efficient path sampling on multiple reaction channels

TL;DR

This paper reviews recent advancements in path sampling methods, especially transition interface sampling and parallel path swapping, to efficiently explore multiple reaction channels in complex systems with rare events.

Contribution

It introduces the parallel path swapping algorithm and discusses how path sampling reduces dependence on reaction coordinate choice in multi-channel systems.

Findings

Transition interface sampling is less sensitive to reaction coordinate choice.

Parallel path swapping improves ergodic sampling in multi-channel systems.

The methods enable better exploration of rare events in complex molecular systems.

Abstract

Due to the time scale problem, rare events are not accessible by straight forward molecular dynamics. The presence of multiple reaction channels complicates the problem even further. The feasibility of the standard free energy based methods relies strongly on the success in finding a proper reaction coordinate. This can be very difficult task in high-dimensional complex systems and even more if several distinct reaction channels exist. Moreover, even if a proper reaction coordinate can be found, ergodic sampling will be a challenge. In this article, we discuss the recent advancements of path sampling methods to tackle this problem. We argue why the path sampling methods, via the transition interface sampling technique, is less sensitive to the choice of reaction coordinate. Moreover, we review a new algorithm, parallel path swapping, that can dramatically improve the ergodic sampling of trajectories for the multiple reaction channel systems.