Noniterative Fermi-Löwdin Orbitals for Self-Interaction Correction.

Area of Science:

• Computational chemistry
• Electronic structure theory
• Quantum chemistry

Background:

• Self-interaction error is a significant issue in density functional theory (DFT).
• Traditional Fermi-Löwdin orbital self-interaction correction (FLOSIC) requires computationally expensive iterative relaxation of Fermi orbital descriptors (FODs).

Purpose of the Study:

• To introduce a computationally efficient noniterative Fermi-Löwdin orbital self-interaction correction (NIFLOSIC) method.
• To provide a scalable alternative to FLOSIC for large-scale electronic structure calculations.

Main Methods:

• Developed NIFLOSIC by eliminating iterative FOD relaxation using selected columns of the density matrix localization scheme.
• Utilized the relationship between the electron localization function and FODs.
• Employed a generalized Kohn-Sham framework with full density relaxation to minimize the Perdew-Zunger energy functional.

Main Results:

• NIFLOSIC generates localized orbitals and FODs in a single, noniterative step.
• The method reproduces results from fully self-consistent FLOSIC calculations.
• Significant reduction in computational cost compared to traditional FLOSIC.

Conclusions:

• NIFLOSIC offers a practical and scalable solution for self-interaction correction in electronic structure.
• The method accurately improves frontier molecular orbital energies and dipole moments.
• NIFLOSIC is suitable for large-scale applications despite total electronic energy not being ideal for thermochemistry.