Communication: Kinetic and pairing contributions in the dielectric spectra of electrolyte solutions

Author(s)
M. Sega, S. S. Kantorovich, C. Holm, A. Arnold
Abstract

In the late 1970s, Hubbard and Onsager predicted that adding salt to a polar solution would result in a reduced dielectric permittivity that arises from the unexpected tendency of solvent dipoles to align opposite to the applied field. Here we develop a novel non-equilibrium molecular dynamics simulation approach to determine this decrement accurately. Using a thermodynamic consistent allatom force field we show that for an aqueous solution containing sodium chloride around 4.8 mol/l, this effect accounts for 12% of the total dielectric permittivity. The dielectric decrement can be strikingly different if a less accurate force field for the ions is used. Using the widespread GROMOS parameters, we observe in fact an increment of the dielectric permittivity rather than a decrement, caused by ion pairing and introduced by a too low dispersion force.

Organisation(s)
Department of Computational Biological Chemistry, Computational and Soft Matter Physics
External organisation(s)
Ural Federal University, Universität Stuttgart
Journal
Journal of Chemical Physics
Volume
140
No. of pages
5
ISSN
0021-9606
DOI
https://doi.org/10.1063/1.4880237
Publication date
06-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
104017 Physical chemistry, 103006 Chemical physics
Keywords
ASJC Scopus subject areas
General Physics and Astronomy, Physical and Theoretical Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/1724dc0e-5384-485d-95b6-a503dceee6f9