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Fitting properties from density functional theory based molecular dynamics simulations to parameterize a rigid water force field

Sala, Jonàs and Guàrdia, Elvira and Martí, Jordi and Spangberg, Daniel and Masia, Marco (2012) Fitting properties from density functional theory based molecular dynamics simulations to parameterize a rigid water force field. The Journal of Chemical Physics, Vol. 136 (5). eISSN 1089-7690. Article.

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DOI: 10.1063/1.3679402

Abstract

In the quest towards coarse-grained potentials and new water models, we present an extension of the force matching technique to parameterize an all-atom force field for rigid water. The methodology presented here allows to improve the matching procedure by first optimizing the weighting exponents present in the objective function. A new gauge for unambiguously evaluating the quality of the fit has been introduced; it is based on the root mean square difference of the distributions of target properties between reference data and fitted potentials. Four rigid water models have been parameterized; the matching procedure has been used to assess the role of the ghost atom in TIP4P-like models and of electrostatic damping. In the former case, burying the negative charge inside the molecule allows to fit better the torques. In the latter, since short-range interactions are damped, a better fit of the forces is obtained. Overall, the best performing model is the one with a ghost atom and with electrostatic damping. The approach shown in this paper is of general validity and could be applied to any matching algorithm and to any level of coarse graining, also for non-rigid molecules.

Item Type:Article
ID Code:8461
Status:Published
Refereed:Yes
Uncontrolled Keywords:Density functional theory, liquid theory, molecular dynamics method, molecular force constants, water
Subjects:Area 03 - Scienze chimiche > CHIM/02 Chimica fisica
Divisions:002 Altri enti e centri di ricerca del Nord Sardegna > CNR-Consiglio Nazionale delle Ricerche
001 Università di Sassari > 01-a Nuovi Dipartimenti dal 2012 > Chimica e Farmacia
Publisher:American Institute of Physics
eISSN:1089-7690
Deposited On:11 Dec 2012 10:19

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