Self-interaction-corrected Kohn-Sham effective potentials using the density-consistent effective potential method.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Density functional theory (DFT) and beyond-DFT methods are crucial for understanding molecular and solid electronic structures.
• Kohn-Sham eigenvalues, except for the highest occupied orbital, do not directly represent electron removal energies.
• Approximate density functionals suffer from self-interaction (SI) errors, causing underestimation of ionization energies.

Purpose of the Study:

• To implement and adapt the density-consistent effective potential method for accurate electronic structure calculations.
• To correct self-interaction errors in density functional approximations.
• To improve the prediction of photoelectron spectra and HOMO-LUMO gaps.

Main Methods:

• Adaptation and implementation of the density-consistent effective potential method.
• Utilizing the Fermi-Löwdin orbital self-interaction correction scheme.
• Calculation of SI-corrected local effective potentials, Fermi-Löwdin orbitals, and density.

Main Results:

• Accurate calculation of density of states (photoelectron spectra) and HOMO-LUMO gaps for molecules and polyacenes.
• Demonstrated good agreement between calculated and experimental values.
• Showcased superior performance compared to SI uncorrected density functional approximations.

Conclusions:

• The implemented method effectively corrects self-interaction errors in DFT.
• This approach provides a more accurate prediction of electronic properties, including ionization energies and spectra.
• The findings offer a valuable tool for computational studies in chemistry and materials science.