Kramers turnover: from energy diffusion to spatial diffusion using metadynamics

TL;DR

This paper evaluates the effectiveness of infrequent metadynamics in calculating transition rates of particles between metastable states across different coupling regimes, bridging energy and spatial diffusion.

Contribution

It demonstrates that infrequent metadynamics accurately estimates transition rates across a range of coupling strengths, extending its applicability from energy to spatial diffusion regimes.

Findings

Method performs well in strong coupling regime

Method is effective in weak coupling regime

Approach bridges energy and spatial diffusion regimes

Abstract

We consider the rate of transition for a particle between two metastable states coupled to a thermal environment for various magnitudes of the coupling strength, using the recently proposed infrequent metadynamics approach (Tiwary and Parrinello, Phys. Rev. Lett. 111, 230602 (2013)). We are interested in understanding how this approach for obtaining rate constants performs as the dynamics regime changes from energy diffusion to spatial diffusion. Reassuringly, we find that the approach works remarkably well for various coupling strengths in the strong coupling regime, and to some extent even in the weak coupling regime.