Combining Metadynamics and Integrated Tempering Sampling

TL;DR

This paper introduces a novel method combining metadynamics and integrated tempering sampling to enhance the simulation of rare events, demonstrating significant acceleration in exploring complex systems like silica and chemical reactions.

Contribution

The paper presents a new combined approach that integrates metadynamics with integrated tempering sampling, improving efficiency in atomistic simulations of rare events.

Findings

Over an order of magnitude acceleration in silica simulations

Effective exploration of energy and temperature space

Applicable to chemical reactions and phase transitions

Abstract

The simulation of rare events is one of the key problems in atomistic simulations. Towards its solution a plethora of methods have been proposed. Here we combine two such methods metadynamics and inte-grated tempering sampling. In metadynamics the fluctuations of a carefully chosen collective variable are amplified, while in integrated tempering sampling the system is pushed to visit an approximately uniform interval of energies and allows exploring a range of temperatures in a single run. We describe our ap-proach and apply it to the two prototypical systems a SN2 chemical reaction and to the freezing of silica. The combination of metadynamics and integrated tempering sampling leads to a powerful method. In par-ticular in the case of silica we have measured more than one order of magnitude acceleration.