Michele Invernizzi^1*, Michele Parrinello^2*

1 Department of Physics, ETH Zurich c/o USI Campus, 6900 Lugano, Switzerland

2 Department of Chemistry and Applied Biosciences, ETH Zurich c/o USI Campus, 6900 Lugano, Switzerland

* Corresponding authors emails: michele.invernizzi@phys.chem.ethz.ch, michele.parrinello@phys.chem.ethz.ch

DOI10.24435/materialscloud:2019.0004/v3 [version v3]

Publication date: May 21, 2019

How to cite this record

Michele Invernizzi, Michele Parrinello, Making the best of a bad situation: a multiscale approach to free energy calculation, Materials Cloud Archive 2019.0004/v3 (2019), https://doi.org/10.24435/materialscloud:2019.0004/v3

Description

Many enhanced sampling techniques rely on the identification of a number of collective variables that describe all the slow modes of the system. By constructing a bias potential in this reduced space one is then able to sample efficiently and reconstruct the free energy landscape. In methods like metadynamics, the quality of these collective variables plays a key role in convergence efficiency. Unfortunately in many systems of interest it is not possible to identify an optimal collective variable, and one must deal with the non-ideal situation of a system in which some slow modes are not accelerated. We propose a two-step approach in which, by taking into account the residual multiscale nature of the problem, one is able to significantly speed up convergence. To do so, we combine an exploratory metadynamics run with an optimization of the free energy difference between metastable states, based on the recently proposed variationally enhanced sampling method. This new method is well parallelizable and is especially suited for complex systems, because of its simplicity and clear underlying physical picture.

Materials Cloud sections using this data

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File name	Size	Description
figures.zip MD5md5:61e04ef11828c4401377cee63b7b056c	59.1 MiB	data and scripts for reproducing the paper's figures
inputs.zip MD5md5:657332a4c67841cfe477330988575d9c	62.1 KiB	input files for the simulations

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External references

Keywords

enhanced sampling free energy metadynamics