Osmotic coefficients of atomistic NaCl (aq) force fields
2006 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 124, no 16, 164509- p.Article in journal (Refereed) Published
Solvated ions are becoming increasingly important for (bio)molecular simulations. But there are not much suitable data to validate the intermediate-range solution structure that ion-water force fields produce. We compare six selected combinations of four biomolecular Na-Cl force fields and four popular water models by means of effective ion-ion potentials. First we derive an effective potential at high dilution from simulations of two ions in explicit water. At higher ionic concentration multibody effects will become important. We propose to capture those by employing a concentration dependent dielectric permittivity. With the so obtained effective potentials we then perform implicit solvent simulations. We demonstrate that our effective potentials accurately reproduce ion-ion coordination numbers and the local structure. They allow us furthermore to calculate osmotic coefficients that can be directly compared with experimental data. We show that the osmotic coefficient is a sensitive and accurate measure for the effective ion-ion interactions and the intermediate-range structure of the solution. It is therefore a suitable and useful quantity for validating and parametrizing atomistic ion-water force fields.
Place, publisher, year, edition, pages
2006. Vol. 124, no 16, 164509- p.
IdentifiersURN: urn:nbn:se:kth:diva-83077DOI: 10.1063/1.2185105ISI: 000237136700028PubMedID: 16674148OAI: oai:DiVA.org:kth-83077DiVA: diva2:498666
QC 201203072012-02-122012-02-122012-03-07Bibliographically approved