Simple Fully Nonlocal Density Functionals for Electronic Repulsion Energy.

Area of Science:

• Quantum Chemistry
• Computational Materials Science
• Theoretical Physics

Background:

• Standard density functional theory (DFT) functionals often struggle with strong correlation effects.
• Accurate modeling of electronic repulsion energy is crucial for predicting material properties.
• Existing functionals may lack the necessary nonlocality to describe complex electronic interactions.

Purpose of the Study:

• To develop a self-interaction-free functional for electronic repulsion energy.
• To accurately capture strong correlation effects, particularly during chemical bond dissociation.
• To go beyond the limitations of current DFT functionals by incorporating nonlocality.

Main Methods:

• Constructed a nonlocal functional based on a simplified strong coupling limit.
• Ensured the functional is self-interaction free.
• Utilized integrals of the electron density as a key component, moving beyond the "Jacob's ladder" approach.

Main Results:

• The developed functional provides locally accurate energy densities with correct asymptotic behavior.
• Successfully captured strong correlation effects in bond dissociation without error cancellation.
• Demonstrated the efficacy of highly nonlocal structures in improving upon standard DFT functionals.

Conclusions:

• The novel nonlocal functional offers a promising advancement for describing strongly correlated systems.
• This approach provides a pathway to more accurate electronic structure calculations.
• Future work can focus on incorporating the kinetic energy component for a complete exchange-correlation functional.