Elevating density functional theory to chemical accuracy for water simulations through a density-corrected many-body formalism

Saswata Dasgupta,Eleftherios Lambros,Francesco Paesani,John P Perdew

doi:10.1038/s41467-021-26618-9

Saswata Dasgupta, Eleftherios Lambros + Show 2 more

Open Access

https://doi.org/10.1038/s41467-021-26618-9

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Abstract

Density functional theory (DFT) has been extensively used to model the properties of water. Albeit maintaining a good balance between accuracy and efficiency, no density functional has so far achieved the degree of accuracy necessary to correctly predict the properties of water across the entire phase diagram. Here, we present density-corrected SCAN (DC-SCAN) calculations for water which, minimizing density-driven errors, elevate the accuracy of the SCAN functional to that of “gold standard” coupled-cluster theory. Building upon the accuracy of DC-SCAN within a many-body formalism, we introduce a data-driven many-body potential energy function, MB-SCAN(DC), that quantitatively reproduces coupled cluster reference values for interaction, binding, and individual many-body energies of water clusters. Importantly, molecular dynamics simulations carried out with MB-SCAN(DC) also reproduce the properties of liquid water, which thus demonstrates that MB-SCAN(DC) is effectively the first DFT-based model that correctly describes water from the gas to the liquid phase.

Highlights

Density functional theory (DFT) has been extensively used to model the properties of water
We introduce here a data-driven many-body potential energy function (PEF) for water, MB-strongly constrained and appropriately normed (SCAN)(DC), which is rigorously derived within a many-body formalism applied to density-corrected SCAN (DC-SCAN) data for individual manybody contributions to the interaction energies between water molecules
We have demonstrated that the density-corrected SCAN (DC-SCAN) functional effectively removes density-driven errors from the water 2-body energies, which brings both binding and interaction energies of different water clusters very close to reference values calculated at CCSD(T)/complete basis set (CBS) level of theory

Summary

Introduction

Density functional theory (DFT) has been extensively used to model the properties of water. The simplest XC functional, the local spin density approximation (LSDA)[19,20,21], was shown to correctly predict the structure of metallic crystals under pressure[22,23,24], but was unable to fulfill its promises for water simulations, overestimating the strength of the hydrogen bonds and, predicting a too packed and overstructured liquid phase[25,26]. These limitations hindered the ability of the LSDA functional to describe the properties of water, even qualitatively. It was found that GGA functionals generally underestimate the density of liquid water, while predicting denser ice phases[38]

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