SAFT-γ force field for the simulation of molecular fluids: 4. A single-site coarse-grained model of water applicable over a wide temperature range
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Published version
Accepted version
Author(s)
Type
Journal Article
Abstract
In this work, we develop coarse-grained (CG) force fields for water, where the effective CG intermolecular interactions between particles are estimated from an accurate description of the macroscopic experimental vapour-liquid equilibria data by means of a molecular-based equation of state. The statistical associating fluid theory for Mie (generalised Lennard-Jones) potentials of variable range (SAFT-VR Mie) is used to parameterise spherically symmetrical (isotropic) force fields for water. The resulting SAFT-γ CG models are based on the Mie (8-6) form with size and energy parameters that are temperature dependent; the latter dependence is a consequence of the angle averaging of the directional polar interactions present in water. At the simplest level of CG where a water molecule is represented as a single bead, it is well known that an isotropic potential cannot be used to accurately reproduce all of the thermodynamic properties of water simultaneously. In order to address this deficiency, we propose two CG potential models of water based on a faithful description of different target properties over a wide range of temperatures: our CGW1-vle model is parameterised to match the saturated-liquid density and vapour pressure; our other CGW1-ift model is parameterised to match the saturated-liquid density and vapour-liquid interfacial tension. A higher level of CG corresponding to two water molecules per CG bead is also considered: the corresponding CGW2-bio model is developed to reproduce the saturated-liquid density and vapour-liquid interfacial tension in the physiological temperature range, and is particularly suitable for the large-scale simulation of bio-molecular systems. A critical comparison of the phase equilibrium and transport properties of the proposed force fields is made with the more traditional atomistic models.
Date Issued
2015-05-19
Date Acceptance
2014-12-29
Citation
Molecular Physics, 2015, 113 (9-10), pp.1228-1249
ISSN
1362-3028
Publisher
Taylor & Francis
Start Page
1228
End Page
1249
Journal / Book Title
Molecular Physics
Volume
113
Issue
9-10
Copyright Statement
© 2015 The Author(s). Published by Taylor & Francis.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The moral rights of the named author(s) have been asserted.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The moral rights of the named author(s) have been asserted.
License URL
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/E016340/1
EP/J014958/1
Subjects
Science & Technology
Physical Sciences
Chemistry, Physical
Physics, Atomic, Molecular & Chemical
Chemistry
Physics
interfacial properties
molecular simulation
aqueous systems
force fields
DENSITY-FUNCTIONAL THEORY
EQUATION-OF-STATE
VAPOR-LIQUID-EQUILIBRIA
MONTE-CARLO-SIMULATION
DYNAMICS SIMULATIONS
PHASE-EQUILIBRIA
INTERFACIAL-TENSION
POTENTIAL FUNCTIONS
PERTURBATION-THEORY
POLARIZABLE MODEL
0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics
0306 Physical Chemistry (incl. Structural)
0307 Theoretical and Computational Chemistry
Chemical Physics
Publication Status
Published
Date Publish Online
2015-03-31