Free energy reconstruction from steered dynamics without post-processing |
| |
Authors: | Manuel Athènes Mihai-Cosmin Marinica |
| |
Institution: | 1. Service de Recherches de Métallurgie Physique, Département des Matériaux pour le Nucléaire, CEA Saclay, F-91191 Gif-sur-Yvette, France;2. Condensed Matter and Materials Division, Physics and Life Sciences Directorate, LLNL, Livermore, CA 94551, USA |
| |
Abstract: | Various methods achieving importance sampling in ensembles of nonequilibrium trajectories enable one to estimate free energy differences and, by maximum-likelihood post-processing, to reconstruct free energy landscapes. Here, based on Bayes theorem, we propose a more direct method in which a posterior likelihood function is used both to construct the steered dynamics and to infer the contribution to equilibrium of all the sampled states. The method is implemented with two steering schedules. First, using non-autonomous steering, we calculate the migration barrier of the vacancy in Fe-α. Second, using an autonomous scheduling related to metadynamics and equivalent to temperature-accelerated molecular dynamics, we accurately reconstruct the two-dimensional free energy landscape of the 38-atom Lennard-Jones cluster as a function of an orientational bond-order parameter and energy, down to the solid–solid structural transition temperature of the cluster and without maximum-likelihood post-processing. |
| |
Keywords: | Free-energy calculations Statistical thermodynamics Computer chemistry Molecular simulation Monte Carlo method |
本文献已被 ScienceDirect 等数据库收录! |
|