  In this work we present the dielectric behavior of water with a novel
flexible model that improved all three sites water models Different
concentrations of the ionic liquid 1- butyl-3-methylimidazolium [bmim]
bis(trifluoromethanesulfonyl)imide [Tf 2 N] with water was investigated. The
study was performed by molecular dynamics simulations using three water models,
being two non-polarizable 3-site SPC/E and SPC/e, and a novel flexible 3-site
FAB/epsilon model. Systematic thermodynamics, dynamical and dielectric
properties were investigated, such as density, diffusion coefficient, heat of
vaporization Delta-Hvap, and surface tension at 300 K and 1 bar. We
extrapolated the experimental molar fraction of the mixtures and a pattern
change for all properties was observed, evidencing the phase separation
previously reported by experimental data. The results also display the
dielectric effect of the system on the calculated properties.
