Dynamical Rare event simulation techniques for equilibrium and non-equilibrium systems

TL;DR

This paper reviews advanced rare event simulation techniques used to efficiently generate dynamical pathways over high free energy barriers in molecular systems, comparing their advantages and limitations through numerical tests.

Contribution

It provides a comprehensive overview and comparison of multiple rare event simulation methods, highlighting their strengths, weaknesses, and pitfalls in both equilibrium and non-equilibrium systems.

Findings

Numerical results reveal pitfalls of current non-equilibrium methods.

Comparison highlights advantages and disadvantages of each technique.

Caution is advised when interpreting results from these methods.

Abstract

I give an overview of rare event simulation techniques to generate dynamical pathways across high free energy barriers. The methods on which I will concentrate are the reactive flux approach, transition path sampling, (replica-exchange) transition interface sampling, partial path sampling/milestoning, and forward flux sampling. These methods have in common that they aim to simulate true molecular dynamics trajectories at a much faster rate than naive brute force molecular dynamics. The advantages and disadvantages of these methods are discussed and compared for a simple one-dimensional test system. These numerical results reveal some important pitfalls of the present non-equilibrium methods that have no easy solution and show that caution is necessary when interpreting their results.