  The correct description of the ionic interaction and stable equilibrium of
the simulations of biomolecular structure, dynamics, folding, catalysis, and
function, an accurate model of the monovalent ions is very important. The force
field needs to reproduce coincident many properties of ions, like their
structure, solvation, and moreover both the interactions of these ions with
each other in the crystal and in solution and the interactions of ions with
other molecules. Using a similar strategy employed in the parameterization of
the NaCl/epsilon , in this paper, we first propose a force field for the
Potassium Bromide, the KBr/epsilon. This new model is compared with the
experimental values of cristal density and structure for the salt and the
density, the viscosity, the dielectric constant and the solubility in the water
solution for a range of concentrations. Next, the transferability, of this new
model KBr/epsilon and the NaCl/epsilon, is verified by creating the KCl/epsilon
and the NaBr/epsilon models. The strategy is to employ the same parameters
obtained for the NaCl/epsilon and for the KBr/epsilon force fields. The two new
models derived are also compared with the experimental values for the density,
the viscosity, the dielectric constant and the solubility in the water solution
for a range of concentrations.
