Ab initio theory and modeling of water

TL;DR

This paper demonstrates that the SCAN density functional enables a fully ab initio, predictive model of water, accurately capturing its structural, electronic, and dynamic properties, thus advancing the study of aqueous processes.

Contribution

The study shows that the SCAN functional provides a comprehensive ab initio description of water, including its phase differences and interactions, which was previously elusive.

Findings

SCAN accurately predicts water and ice densities.

It captures the balance of covalent, hydrogen, and van der Waals interactions.

The approach enables efficient, predictive modeling of aqueous systems.

Abstract

Water is of the utmost importance for life and technology. However, a genuinely predictive ab initio model of water has eluded scientists. We demonstrate that a fully ab initio approach, relying on the strongly constrained and appropriately normed (SCAN) density functional, provides such a description of water. SCAN accurately describes the balance among covalent bonds, hydrogen bonds, and van der Waals interactions that dictates the structure and dynamics of liquid water. Notably, SCAN captures the density difference between water and ice I{\it h} at ambient conditions, as well as many important structural, electronic, and dynamic properties of liquid water. These successful predictions of the versatile SCAN functional open the gates to study complex processes in aqueous phase chemistry and the interactions of water with other materials in an efficient, accurate, and predictive, ab initio manner.