title: Coarse graining from variationally enhanced sampling applied to the Ginzburg-Landau model.
abstract: A powerful way to deal with a complex system is to build a coarse-grained model capable of catching its main physical features, while being computationally affordable. Inevitably, such coarse-grained models introduce a set of phenomenological parameters, which are often not easily deducible from the underlying atomistic system. We present a unique approach to the calculation of these parameters, based on the recently introduced variationally enhanced sampling method. It allows us to obtain the parameters from atomistic simulations, providing thus a direct connection between the microscopic and the mesoscopic scale. The coarse-grained model we consider is that of Ginzburg-Landau, valid around a second-order critical point. In particular, we use it to describe a Lennard-Jones fluid in the region close to the liquid-vapor critical point. The procedure is general and can be adapted to other coarse-grained models.
authors.affiliation: Department of Physics, Eidgenössische Technische Hochschule (ETH) Zurich c/o Università della Svizzera Italiana (USI) Campus, 6900 Lugano, Switzerland.|Facoltà di Informatica, Instituto di Scienze Computationali, and National Center for Computational Design and Discovery of Novel Materials MARVEL, Università della Svizzera Italiana, 6900 Lugano, Switzerland.
authors.forename: Michele
authors.initials: M
authors.lastname: Invernizzi
authors.affiliation: Facoltà di Informatica, Instituto di Scienze Computationali, and National Center for Computational Design and Discovery of Novel Materials MARVEL, Università della Svizzera Italiana, 6900 Lugano, Switzerland.|Department of Chemistry and Applied Biosciences, ETH Zurich c/o USI Campus, 6900 Lugano, Switzerland.
authors.forename: Omar
authors.initials: O
authors.lastname: Valsson
authors.affiliation: Facoltà di Informatica, Instituto di Scienze Computationali, and National Center for Computational Design and Discovery of Novel Materials MARVEL, Università della Svizzera Italiana, 6900 Lugano, Switzerland; parrinello@phys.chem.ethz.ch.|Department of Chemistry and Applied Biosciences, ETH Zurich c/o USI Campus, 6900 Lugano, Switzerland.
authors.forename: Michele
authors.initials: M
authors.lastname: Parrinello
keywords: Ginzburg–Landau free energy; Lennard–Jones; coarse graining; enhanced sampling; second-order phase transitions