Gaussian field model for polar fluids as a function of density and polarization: toward a model for water

TL;DR

This paper introduces a Gaussian field model for polar fluids that captures key dielectric and structural features of water, offering a computationally efficient alternative to existing models.

Contribution

It develops a simple Gaussian field framework based on density and polarization to model water's dielectric properties and structure, addressing computational challenges of explicit models.

Findings

Captures quasi-resonant longitudinal dielectric susceptibility

Reproduces two maxima in the structure factor

Provides a computationally efficient modeling approach

Abstract

This work is concerned with a simple model for a polar fluid, a Gaussian field model based on the excess density and on the polarization. It is a convenient framework to implement the dielectric properties of correlated liquids that stem from nanometric correlations between molecules. It allows to study the effects of coupling terms between density and polarization on the structure of the fluid. Despite the simplicity of such a model, it can capture some interesting features of the response functions of water such as the quasi-resonant longitudinal dielectric susceptibility or the presence of two maxima in the structure factor. Explicit models of water generate extremely high computational cost and implicit models sometimes fail to treat properly the electrostatic interactions. A Gaussian field theory could therefore be an interesting alternative to describe water.