Zooming across the Free-Energy Landscape: Shaving Barriers, and Flooding Valleys

• Published in: The journal of physical chemistry letters 2018-08, Vol.9 (16), p.4738-4745
• Main Authors: Fu, Haohao, Zhang, Hong, Chen, Haochuan, Shao, Xueguang, Chipot, Christophe, Cai, Wensheng
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Physics
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.8b01994

A robust importance-sampling algorithm for mapping free-energy surfaces over geometrical variables, coined meta-eABF, is introduced. This algorithm shaves the free-energy barriers and floods valleys by incorporating a history-dependent potential term in the extended adaptive biasing force (eABF) framework. Numerical applications on both toy models and nontrivial examples indicate that meta-eABF explores the free-energy surface significantly faster than either eABF or metadynamics (MtD) alone, without the need to stratify the reaction pathway. In some favorable cases, meta-eABF can be as much as five times faster than other importance-sampling algorithms. Many of the shortcomings inherent to eABF and MtD, like kinetic trapping in regions of configurational space already adequately sampled, the requirement of prior knowledge of the free-energy landscape to set up the simulation, are readily eliminated in meta-eABF. Meta-eABF, therefore, represents an appealing solution for a broad range of applications, especially when both eABF and MtD fail to achieve the desired result.