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

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.