(31h) Investigating Path Sampling Techniques on Complex Energy Landscapes to Study Nucleation

Nucleation is a rare event in molecular simulations and thus, requires enhanced sampling techniques. One category of these are path sampling techniques of which forward flux sampling (FFS) and transition interface sampling (TIS) have been used extensively to study nucleation. These methods have several advantages – they do not bias the dynamics of the systems, they are not dependent on the order parameter, and result in an ensemble of transition paths enabling detailed mechanistic studies of the transition. There are, however, some practical challenges in applying these techniques for complex energy landscapes, which direct affect the efficiency of these methods. In our study we have compared FFS and TIS for nucleation in Lennard Jones systems, which represent a complex energy landscape. We provide in-depth discussion of the methodological details important to ensure the appropriate implementation of these methods. Further, we evaluate the efficiencies of the methods and comment on their relative strengths and weaknesses in context of complex energy landscapes. This study fills a knowledge gap in the field – while many methods are available, and most of them are computationally expensive, it is non-trivial to compare them. Our studies will thus provide insights and guidelines for the selection of appropriate method for rare event simulations to the scientific community.