Self-Interaction Correction in Water-Ion Clusters

Abstract

We study the importance of self-interaction errors in density functional approximations for various water-ion clusters. We have employed the Fermi-Löwdin orbital self-interaction correction (FLOSIC) method in conjunction with LSDA, PBE, and SCAN to describe binding energies of hydrogen-bonded water-ion clusters, \textit{i.e.}, water-hydronium, water-hydroxide, water-halide, as well as non-hydrogen-bonded water-alkali clusters. In the hydrogen-bonded water-ion clusters, the building blocks are linked by hydrogen atoms, although the links are much stronger and longer-ranged than the normal hydrogen bonds between water molecules, because the monopole on the ion interacts with both permanent and induced dipoles on the water molecules. We find that self-interaction errors overbind the hydrogen-bonded water-ion clusters and that FLOSIC reduces the error and brings the binding energies into closer agreement with higher-level calculations. The non-hydrogen-bonded water-alkali clusters are not significantly affected by self-interaction errors. Self-interaction corrected PBE predicts the lowest mean unsigned error in binding energies ($\le$ 50 meV/\ce{H2O}) for hydrogen-bonded water-ion clusters. Self-interaction errors are also largely dependent on the cluster size, and FLOSIC does not accurately capture the subtle variation in all clusters, indicating the need for further refinement.

13 pages, 9 figures

References in corpus (12)

• Ab initio theory and modeling of water
• The Individual and Collective Effects of Exact Exchange and Dispersion Interactions on the Ab Initio Structure of Liquid Water
• On the accuracy of DFT exchange-correlation functionals for H bonds in small water clusters II: The water hexamer and van der Waals interactions
• The Importance of being consistent
• Fermi Orbital Derivatives in Self-Interaction Corrected Density Functional Theory: Applications to Closed Shell Atoms
• A step in the direction of resolving the paradox of Perdew-Zunger self-interaction correction
• Coupled cluster benchmarks of water monomers and dimers extracted from DFT liquid water: the importance of monomer deformations
• Stretched or noded orbital densities and self-interaction correction in density functional theory
• Perdew-Zunger self-interaction correction: How wrong for uniform densities and large-Z atoms?
• Importance of self-interaction-error removal in density functional calculations on water cluster anions
• A Step in the Direction of Resolving the Paradox of Perdew-Zunger Self-interaction Correction. II. Gauge Consistency of the Energy Density at Three Levels of Approximation
• Exploring and enhancing the accuracy of interior-scaled Perdew-Zunger self-interaction correction