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

M. Sega (Korresp. Autor*in), S. S. Kantorovich, C. Holm, A. Arnold

Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed


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.

FachzeitschriftJournal of Chemical Physics
PublikationsstatusVeröffentlicht - 7 Juni 2014

ÖFOS 2012

  • 104017 Physikalische Chemie
  • 103006 Chemische Physik