Three-dimensional "Mercedes-Benz" model for water

TL;DR

This paper introduces a 3D water model combining Lennard-Jones and Gaussian potentials that accurately reproduces water's structural and thermodynamic anomalies, including ice formation and density behavior.

Contribution

The paper presents a novel three-dimensional water model explicitly incorporating van der Waals and hydrogen bonds, capturing key anomalies of water.

Findings

Reproduces main peaks of experimental radial distribution function

Captures thermodynamic anomalies like density and heat capacity

Models ice formation at low temperatures

Abstract

In this paper we introduce a three-dimensional version of the Mercedes-Benz model to describe water molecules. In this model van der Waals interactions and hydrogen bonds are given explicitly through a Lennard-Jones potential and a Gaussian orientation-dependent terms, respectively. At low temperature the model freezes forming Ice-I and it reproduces the main peaks of the experimental radial distribution function of water. In addition to these structural properties, the model also captures the thermodynamical anomalies of water: the anomalous density profile, the negative thermal expansivity, the large heat capacity and the minimum in the isothermal compressibility.