Chemical bonding theories as guides for self-interaction corrections

Fermi-orbital descriptors (FODs), i.e., electron positions, can be used to form Fermi--Löwdin orbitals (FLO), a special set of localized orbitals which can be used in combination with the Perdew--Zunger self-interaction correction (SIC) in the FLO-SIC method. We show how FODs can be used to initialize, interpret and justify SIC solutions in a common chemical picture within various SIC approaches.[1]

Additionally, we show that using Lewis' theory as the starting point can lead to artifactual dipole moments of up to 1 Debye, while Linnett SIC dipole moments are in better agreement with experimental values. We suggest using the dipole moment as a diagnostic of symmetry breaking in SIC and monitoring it in all SIC  calculations. We show that Linnett structures can often be seen as superpositions of Lewis structures and propose Linnett structures as a simple way to describe aromatic systems in SIC with reduced symmetry breaking.[1]

[1] K. Trepte et. al, arXiv:2109.08199 [physics.comp-ph] (2021)