Self-interaction correction for Solvated Anions

Due to unphysical self-interaction error (SIE), density functional approximations (DFAs) predict electronic orbital energies well above experiment, even in neutral systems. The problem becomes especially severe in anionic systems, where positive DFA orbital energies imply unbound electrons. Through the use of the Perdew-Zunger self-interaction correction (PZSIC), within the novel Fermi-Löwdin-orbitals (FLOSIC method) implementation, physically meaningful orbital energies can be obtained for anionic systems. We show this by applying the FLOSIC method to the extreme case of a trianionic Cr complex embedded in a water cluster. A challenge within FLOSIC is the automated determination of an initial starting point for systems as it is a prerequisite to achieving self consistency. Therefore, in this talk, we share a simple but efficient way to meet this challenge. We discuss the degree to which these simplified starting points should be viewed as density-based or density-matrix based starting points. Our results show that the HOMO of the trianion lies below the LUMO states of the water molecules even for the case where the water ball is so large that the water LUMO states reproduce the experimental electron affinity of a water cluster.