Shrinking Self-Interaction Errors with the Fermi–Löwdin Orbital Self-Interaction-Corrected Density Functional Approximation

The self-interaction
error (SIE) is one of the major drawbacks
of practical exchange-correlation functionals for Kohn–Sham
density functional theory. Despite this, the use of methods that explicitly
remove SIE from approximate density functionals is scarce in the literature
due to their relatively high computational cost and lack of consistent
improvement over standard modern functionals. In this article we assess
the performance of a novel approach recently proposed by Pederson,
Ruzsinszky, and Perdew [J. Chem. Phys. 2014, 140, 121103] for performing self-interaction free
calculations in density functional theory based on Fermi orbitals.
To this end, we employ test sets consisting of reaction energies that
are considered particularly sensitive to SIE. We found that the parameter-free
Fermi–Löwdin orbital self-interaction correction method
combined with the standard local spin density approximation (LSDA)
and Perdew–Burke–Ernzerhof (PBE) functionals gives a
much better estimate of reaction energies compared to their parent
LSDA and PBE functionals for most of the reactions in these two sets.
They also perform on par with the global PBE0 and range-separated
LC-ωPBE hybrids, which partially eliminate the SIE by including
Hartree–Fock exchange. This shows the potential of the Fermi–Löwdin
orbital self-interaction correction (FLOSIC) method for practical
density functional calculations without SIE.