Comparison of water models for structure prediction

TL;DR

This study compares 44 classical water models to determine which best reproduces the liquid water structure, finding that four-site TIP4P-type models most accurately match experimental data across temperatures.

Contribution

It provides a comprehensive comparison of classical water potential models, highlighting the effectiveness of four-site TIP4P-type models in structural predictions.

Findings

Four-site TIP4P-type models best match experimental data.

Models with more than four sites or flexible/polarizable models do not significantly improve accuracy.

Recent three-site models show notable progress in structural prediction.

Abstract

Describing the interactions of water molecules is one of the most common, yet critical, tasks in molecular dynamics simulations. Because of its unique properties, hundreds of attempts have been made to construct an ideal interaction potential model for water. In various studies, the models have been evaluated based on their ability to reproduce different properties of water. This work focuses on the atomic-scale structure in the liquid phase of water. Forty-four classical water potential models are compared to identify those that can accurately describe the structure in alignment with experimental results. In addition to some older models that are still popular today, new or re-parametrized classical models using effective pair-additive potentials that have appeared in recent years are examined. Molecular dynamics simulations were performed over a wide range of temperatures and the resulting trajectories were used to calculate the partial radial distribution functions. The total scattering structure factors were compared with data from neutron and X-ray diffraction experiments. Our analysis indicates that models with more than four interaction sites, as well as flexible or polarizable models with higher computational requirements, do not provide a significant advantage in accurately describing the structure. On the other hand, recent three-site models have made considerable progress in this area, although the best agreement with experimental data over the entire temperature range was achieved with four-site, TIP4P-type models.