Self-consistent implementation of locally scaled self-interaction-correction method.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Self-interaction error is a significant limitation in standard density functional approximations (DFAs).
• Existing self-interaction correction (SIC) methods, like Perdew-Zunger SIC (PZSIC), have limitations.
• The local self-interaction correction (LSIC) method offers a promising alternative for correcting these errors.

Purpose of the Study:

• To present the self-consistent implementation of the local self-interaction correction (LSIC) method.
• To incorporate atomic forces and forces on Fermi-Löwdin orbitals within the LSIC framework.
• To evaluate the performance of LSIC using simple density functionals against established methods.

Main Methods:

• Implemented LSIC using the ratio of Weizsäcker and Kohn-Sham kinetic energy densities as an iso-orbital indicator.
• Developed self-consistent calculations for the LSIC energy functional.
• Included the computation of atomic forces and forces on Fermi-Löwdin orbitals.

Main Results:

• LSIC combined with the simplest local spin density functional achieved superior atomization energies (AE6 dataset) compared to PBE.
• LSIC demonstrated improved barrier heights (BH6 database) over hybrid functionals like PBE0 and B3LYP.
• LSIC accurately predicted molecular bond lengths with a mean absolute error of 0.008 Å, outperforming PZSIC-LSDA and LSDA.

Conclusions:

• The LSIC method effectively reduces self-interaction errors in density functional theory.
• Accurate results can be achieved using simple density functionals when self-interaction errors are properly addressed by LSIC.
• LSIC presents a viable and accurate approach for electronic structure calculations.