title: Variationally Optimized Free-Energy Flooding for Rate Calculation.
abstract: We propose a new method to obtain kinetic properties of infrequent events from molecular dynamics simulation. The procedure employs a recently introduced variational approach [Valsson and Parrinello, Phys. Rev. Lett. 113, 090601 (2014)] to construct a bias potential as a function of several collective variables that is designed to flood the associated free energy surface up to a predefined level. The resulting bias potential effectively accelerates transitions between metastable free energy minima while ensuring bias-free transition states, thus allowing accurate kinetic rates to be obtained. We test the method on a few illustrative systems for which we obtain an order of magnitude improvement in efficiency relative to previous approaches and several orders of magnitude relative to unbiased molecular dynamics. We expect an even larger improvement in more complex systems. This and the ability of the variational approach to deal efficiently with a large number of collective variables will greatly enhance the scope of these calculations. This work is a vindication of the potential that the variational principle has if applied in innovative ways.
authors: Department of Chemistry and Applied Biosciences, ETH Zurich and Facoltà di Informatica, Instituto di Scienze Computazionali, Università della Svizzera italiana, Via Giuseppe Buffi 13, CH-6900 Lugano, Switzerland.
authors: James
authors: J
authors: McCarty
authors: Department of Chemistry and Applied Biosciences, ETH Zurich and Facoltà di Informatica, Instituto di Scienze Computazionali, Università della Svizzera italiana, Via Giuseppe Buffi 13, CH-6900 Lugano, Switzerland.|National Center for Computational Design and Discovery of Novel Materials MARVEL, Università della Svizzera italiana, Via Giuseppe Buffi 13, CH-6900 Lugano, Switzerland.
authors: Omar
authors: O
authors: Valsson
authors: Department of Chemistry, Columbia University, New York, New York 10027, USA.
authors: Pratyush
authors: P
authors: Tiwary
authors: Department of Chemistry and Applied Biosciences, ETH Zurich and Facoltà di Informatica, Instituto di Scienze Computazionali, Università della Svizzera italiana, Via Giuseppe Buffi 13, CH-6900 Lugano, Switzerland.|National Center for Computational Design and Discovery of Novel Materials MARVEL, Università della Svizzera italiana, Via Giuseppe Buffi 13, CH-6900 Lugano, Switzerland.
authors: Michele
authors: M
authors: Parrinello