Estimate of the intermolecular polarization contribution to the static dielectric constant of water

Abstract

In this paper, molecular-structure data derived from recent quantum-chemical studies are used in conjunction with the Mandel–Mazur theory of the static dielectric constant to estimate the importance of intermolecular polarization contributions to the static dielectric constant of water. A scalar expression for the static dielectric constant is identified and then investigated via a multibody decomposition in which the effects of 2-, 3-, ... n-body interactions are displayed and then analyzed numerically. Our main conclusion is that the intermolecular polarization contribution is of crucial importance in determining the static dielectric constant of water. Further, our calculations show that the predicted dielectric constant is extraordinarily sensitive to the geometry of the first hydration shell; thus, the use of a slightly inaccurate potential function may lead to a predicted dielectric constant in significant disagreement with the experimental value.