Exploring the idea of self-guided dynamics

We have examined the recently proposed concept of self-guiding in the conte xt of both stochastic and deterministic dynamics of a test particle in a do uble-well potential. In contrast to the original suggestion, results from o ur stochastic dynamics simulations indicate that enhancement of the systema tic part of the force by introduction of a self-guiding term actually decre ases the sampling efficiency of the system. It was found that only by subst antially reducing the correlation between the actual force and the self-gui ding 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 ba rrier crossing rate could be observed for the case when the actual force an d the biasing force were strongly correlated. However, even a moderate deco rrelation resulted in appreciable enhancement in barrier crossings. For the deterministic dynamics of the test particle uncoupled to the bath, no decr ease in sampling was observed. We suggest that depending on the inertial me mory of the system, the degree of correlation between the actual and the bi asing force determines whether sampling will increase or not. This provides a unified picture and gives us insight about the applicability of the meth od under different simulation conditions. (C) 2001 American Institute of Ph ysics.