Exploring the idea of self-guided dynamics

Abstract

We have examined the recently proposed concept of self-guiding in the context of both stochastic and deterministic dynamics of a test particle in a double-well potential. In contrast to the original suggestion, results from our stochastic dynamics simulations indicate that enhancement of the systematic part of the force by introduction of a self-guiding term actually decreases the sampling efficiency of the system. It was found that only by substantially reducing the correlation between the actual force and the self-guiding force an enhancement in sampling could be achieved. In a deterministic analog of the same problem, constructed by coupling the test particle to a bath of a number of harmonic oscillators, an analogous reduction in the barrier crossing rate could be observed for the case when the actual force and the biasing force were strongly correlated. However, even a moderate decorrelation resulted in appreciable enhancement in barrier crossings. For the deterministic dynamics of the test particle uncoupled to the bath, no decrease in sampling was observed. We suggest that depending on the inertial memory of the system, the degree of correlation between the actual and the biasing force determines whether sampling will increase or not. This provides a unified picture and gives us insight about the applicability of the method under different simulation conditions.