Electron affinities of water clusters from density-functional and many-body-perturbation theory

TL;DR

This paper evaluates the accuracy of advanced computational methods like dielectric-dependent hybrid functionals and G0W0 in predicting electron affinities of small water clusters, showing they closely match high-level coupled-cluster results.

Contribution

It demonstrates that G0W0 calculations based on dielectric-dependent hybrids can reliably predict water cluster electron affinities with high accuracy.

Findings

G0W0 with dielectric-dependent hybrids predicts affinities within 0.1 eV of coupled-cluster results.

The methods are validated on water dimer and hexamer isomers.

The approach offers a computationally efficient alternative to high-level quantum chemistry methods.

Abstract

In this work, we assess the accuracy of dielectric-dependent hybrid density functionals and many-body perturbation theory methods for the calculation of electron affinities of small water clusters, including hydrogen-bonded water dimer and water hexamer isomers. We show that many-body perturbation theory in the G$_0$W$_0$ approximation starting with the dielectric-dependent hybrid functionals predicts electron affinities of clusters within 0.1 eV of the coupled-cluster results with single, double, and perturbative triple excitations.