Navigating the complexities of rare events! This review delves into the concepts and methodologies of transition path sampling, a suite of computational techniques designed to study rare events without prior knowledge of mechanisms, reaction coordinates, or transition states. It highlights how transition path sampling provides a unique perspective on time-dependent phenomena, even in systems far from equilibrium. Based on the statistical mechanics of trajectory space, transition path sampling employs importance sampling tools to examine these phenomena. This method creates ensembles of trajectories connecting reactant and product states, allowing researchers to visualize and characterize rare transitions. Transition path sampling overcomes limitations of traditional methods by not requiring pre-defined reaction coordinates or knowledge of the transition state, enabling the investigation of complex systems where the reaction pathway is unknown. The transition path sampling approach allows the effective examination of time-dependent phenomena, contributing to advancements in chemical kinetics, materials science, and biophysics. It enables simulations that previously were intractable, expanding the scope of computational studies of rare events, molecular dynamics, and sampling tools.
As a review in the Annual Review of Physical Chemistry, this paper perfectly suits the journal's scope by providing a comprehensive overview of transition path sampling. It emphasizes the method's utility in studying rare events, a crucial topic in physical chemistry, and its application to complex systems, appealing to the journal's audience of physical and theoretical chemists.