Exploring and enhancing the accuracy of interior-scaled Perdew-Zunger self-interaction correction

Area of Science:

• Quantum Chemistry
• Computational Materials Science

Background:

• Perdew-Zunger self-interaction correction (PZ-SIC) improves density functional approximations but overcorrects equilibrium properties.
• Local scaling self-interaction correction (LSIC) reduces this overcorrection in the local spin density approximation (LSDA).

Purpose of the Study:

• To develop a new scaling factor for LSIC-like methods that satisfies the correct atomic exchange-correlation energy coefficient.
• To improve the accuracy of density functional approximations for various chemical properties, including weak bond interactions.

Main Methods:

• Proposed a new scaling factor for LSIC methods based on the iso-orbital indicator.
• Applied LSIC+ to LSDA and developed SCAN-sdSIC for functionals beyond LSDA.
• Evaluated methods on atomic and molecular properties, including equilibrium properties and dissociation energies of weak bonds.

Main Results:

• LSIC+ applied to LSDA shows improved performance for equilibrium properties compared to LSDA-LSIC and GGA, approaching SCAN meta-GGA accuracy.
• LSDA-LSIC and LSDA-LSIC+ struggle with weak bond interaction energies.
• SCAN-sdSIC accurately describes equilibrium properties and weak bond dissociation energies.

Conclusions:

• The proposed scaling factor and SCAN-sdSIC offer a more accurate description of electronic properties, addressing limitations of previous SIC methods.
• Consistent chemical interpretation of localized SIC orbitals requires new selection criteria for Fermi orbital descriptors.
• The developed methods provide a better balance for describing both strong and weak interactions in density functional theory.