A molecular dynamics study of dielectric constant of water from ambient to sub- and supercritical conditions using a fluctuating-charge potential model

Molecular dynamics calculations have been performed based upon a fluctuating-charge model TIP4P-FQ over a wide range of state points from ambient to sub- and supercritical conditions in order to investigate dielectric properties of water. The TIP4P-FQ could successfully reproduce the experimental dielectric constant. The dielectric constant is dominated not only by the intermolecular orientational correlation but also by the magnitude of each molecular dipole moment. Interesting behavior of these two contributions is reported as a function of temperature and density. Averaged number of hydrogen bonds has also been found to have a strong correlation with the dielectric constant.