Practical guide to replica exchange transition interface sampling and forward flux sampling

TL;DR

This paper provides a practical guide for analyzing and assessing the quality of replica exchange transition interface sampling (RETIS) and forward flux sampling (FFS) simulations, crucial for studying rare events in complex molecular systems.

Contribution

It introduces analysis tools and step-wise evaluation methods to ensure the reliability and convergence of RETIS and FFS simulations in complex systems.

Findings

Assessment tools for simulation quality and convergence

Application to nucleation in various systems

Guidelines for reliable RETIS and FFS simulations

Abstract

Path sampling approaches have become invaluable tools to explore the mechanisms and dynamics of so-called rare events that are characterized by transitions between metastable states separated by sizeable free energy barriers. Their practical application, in particular to ever more complex molecular systems, is, however, not entirely trivial. Focusing on replica exchange transition interface sampling (RETIS) and forward flux sampling (FFS), we discuss a range of analysis tools that can be used to assess the quality and convergence of such simulations which is crucial to obtain reliable results. The basic ideas of a step-wise evaluation are exemplified for the study of nucleation in several systems with different complexity, providing a general guide for the critical assessment of RETIS and FFS simulations.