Nuclear quantum effects in water

TL;DR

This paper demonstrates that incorporating nuclear quantum effects in molecular dynamics simulations significantly enhances the accuracy of liquid water models, aligning them more closely with experimental data, especially in proton momentum distribution.

Contribution

It introduces a path integral Car-Parrinello molecular dynamics approach to include nuclear quantum effects in water simulations, improving agreement with experiments.

Findings

Quantum effects improve simulation accuracy

Proton momentum distribution matches neutron scattering data

Method applicable to liquid water and ice

Abstract

In this work, a path integral Car-Parrinello molecular dynamics simulation of liquid water is performed. It is found that the inclusion of nuclear quantum effects systematically improves the agreement of first principles simulations of liquid water with experiment. In addition, the proton momentum distribution is computed utilizing a recently developed open path integral molecular dynamics methodology. It is shown that these results are in good agreement with neutron Compton scattering data for liquid water and ice.