Ab-initio molecular dynamics simulation of liquid water by Quantum Monte Carlo

TL;DR

This paper demonstrates a room temperature ab-initio molecular dynamics simulation of liquid water using quantum Monte Carlo methods, achieving results that align well with experimental data and surpassing previous density functional theory approaches.

Contribution

It introduces a novel QMC-based simulation of liquid water at room temperature, highlighting its accuracy and potential for complex chemical systems.

Findings

Good agreement with neutron scattering and X-ray experiments

Accurate prediction of oxygen-oxygen radial distribution function

QMC's scalability enables reliable large-scale simulations

Abstract

Although liquid water is ubiquitous in chemical reactions at roots of life and climate on the earth, the prediction of its properties by high-level ab initio molecular dynamics simulations still represents a formidable task for quantum chemistry. In this article we present a room temperature simulation of liquid water based on the potential energy surface obtained by a many-body wave function through quantum Monte Carlo (QMC) methods. The simulated properties are in good agreement with recent neutron scattering and X-ray experiments, particularly concerning the position of the oxygen-oxygen peak in the radial distribution function, at variance of previous Density Functional Theory attempts. Given the excellent performances of QMC on large scale supercomputers, this work opens new perspectives for predictive and reliable ab-initio simulations of complex chemical systems.