Liquid Water through Density-Functional Molecular Dynamics: Plane-Wave vs Atomic-Orbital Basis Sets

TL;DR

This study compares the structural, dynamical, and electronic properties of liquid water using density-functional molecular dynamics with plane-wave and atomic-orbital basis sets, finding they produce equivalent results.

Contribution

It demonstrates that plane-wave and atomic-orbital basis sets yield consistent results in simulating liquid water, validating their interchangeable use in such studies.

Findings

Excellent agreement between the two basis set frameworks.

Both methods accurately reproduce liquid water properties.

Supports interchangeable use of basis sets in water simulations.

Abstract

We determine and compare structural, dynamical, and electronic properties of liquid water at near ambient conditions through density-functional molecular dynamics simulations, when using either plane-wave or atomic-orbital basis sets. In both frameworks, the electronic structure and the atomic forces are self-consistently determined within the same theoretical scheme based on a nonlocal density functional accounting for van der Waals interactions. The overall properties of liquid water achieved within the two frameworks are in excellent agreement with each other. Thus, our study supports that implementations with plane-wave or atomic-orbital basis sets yield equivalent results and can be used indiscriminately in study of liquid water or aqueous solutions.