title: Communication: Kinetic and pairing contributions in the dielectric spectra of electrolyte solutions.
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 all-atom 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.
authors.affiliation: Institut für Computergestützte Biologische Chemie, University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Sega
authors.affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria and Ural Federal University, Lenin av. 51, 620083 Ekaterinburg, Russia.
authors.forename: S S
authors.initials: SS
authors.lastname: Kantorovich
authors.affiliation: Institut für Computerphysik, Universität Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Holm
authors.affiliation: Institut für Computerphysik, Universität Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Arnold
mesh_terms: D017606:Chlorine Compounds / Q000737:chemistry; D004573:Electrolytes / Q000737:chemistry*; D007700:Kinetics; D056004:Molecular Dynamics Simulation; D011188:Potassium / Q000737:chemistry; D012492:Salts / Q000737:chemistry; D012964:Sodium / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D017606:Chlorine Compounds; D004573:Electrolytes; D012492:Salts; D012996:Solutions; D012997:Solvents; D014867:Water; D012964:Sodium; D011188:Potassium