Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Kinetic and ion pairing contributions in the dielectric spectra of
  electrolyte aqueous solutions   Understanding dielectric spectra can reveal important information about the
dynamics of solvents and solutes from the dipolar relaxation times down to
electronic ones. In the late 1970s, Hubbard and Onsager predicted that adding
salt ions 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. So far, this effect has escaped an experimental
verification, mainly because of the concomitant appearance of dielectric
saturation from which the Hubbard-Onsager decrement cannot be easily separated.
Here we develop a novel non-equilibrium molecular dynamics simulation approach
to determine this decrement accurately for the first time. 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 {\it increment} of the
dielectric permittivity rather than a decrement. We can show that this
increment is caused by ion pairing, introduced by a too low dispersion force,
and clarify the microscopic connection between long-living ion pairs and the
appearance of specific features in the dielectric spectrum of the solution.

35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an