Nonlocal Functionals Inspired by the Strongly Interacting Limit of DFT: Exact Constraints and Implementation

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Accurately describing electron correlation is crucial for density functional theory (DFT) accuracy.
• Existing methods struggle with strong correlation effects, limiting predictive power.
• The multiple radii functional (MRF) offers a promising framework for strong correlation.

Purpose of the Study:

• To investigate and refine the multiple radii functional (MRF) for improved exchange-correlation (XC) functional development.
• To enhance the MRF's ability to capture strong correlation effects in DFT.
• To develop more efficient implementations of the MRF.

Main Methods:

• Theoretical analysis of the MRF applied to uniform and scaled electron densities.
• Development of improved fluctuation functions within the MRF framework.
• Implementation of MRF using Gaussian basis sets for enhanced efficiency.

Main Results:

• The MRF demonstrates accurate XC energy densities and is free from self-interaction errors.
• Improved fluctuation functions are derived, enhancing MRF's applicability across correlation regimes.
• Gaussian basis set implementation significantly boosts computational efficiency over grid-based methods.

Conclusions:

• The MRF provides a versatile and accurate framework for developing advanced XC functionals.
• Refinements enable precise modeling of both physical and infinite correlation limits.
• Efficient implementation paves the way for broader application of MRF in DFT.