Weighted Ensemble Path Sampling for Multiple Reaction Channels

TL;DR

This paper demonstrates that the weighted ensemble path sampling method effectively samples multiple reaction channels in molecular transitions, providing a practical approach for complex systems where brute-force methods are infeasible.

Contribution

The study introduces the application of weighted ensemble path sampling to efficiently explore multiple reaction channels in molecular systems, outperforming traditional methods in complex scenarios.

Findings

WE can sample multiple channels without trapping.

WE provides accurate fractional importance of channels.

Method works at biologically relevant temperatures.

Abstract

Finding and sampling multiple reaction channels for molecular transitions remains an important challenge in physical chemistry. Here we show that the weighted ensemble (WE) path sampling method can readily sample multiple channels. In a first test, both the WE and transition path sampling methods are applied to two-dimensional model potentials. The comparison explains why the weighted ensemble approach will not be trapped in one channel. The WE approach is then used to sample the full transition path ensemble in implicitly solvated alanine dipeptide at two different temperatures. The ensembles are of sufficient quality to permit quantification of the fractional importance of each channel, even at T=300K when brute-force simulation is prohibitively expensive.