A first-principles-based correlation functional for harmonious connection of short-range correlation and long-range...

Area of Science:

• Quantum Chemistry
• Computational Materials Science
• Electronic Structure Theory

Background:

• Accurate description of electron correlation is crucial for predicting molecular properties.
• Existing meta-generalized gradient approximation (meta-GGA) functionals often struggle with long-range van der Waals interactions.
• Combining semilocal functionals with dispersion corrections can lead to double-counting issues.

Purpose of the Study:

• To develop a physically motivated meta-GGA correlation functional.
• To enable seamless integration with long-range dispersion corrections without double-counting.
• To provide a robust and accurate method for calculating interaction energies, particularly for non-covalently bound systems.

Main Methods:

• Derivation of the correlation functional using constraint satisfaction and an analytical real-space correlation hole model.
• Inclusion of a position-dependent function to control the range of semilocal correlations.
• Combination with atom-pairwise dispersion corrections and Hartree-Fock (HF)-like exchange for preliminary assessment.

Main Results:

• The developed meta-GGA functional effectively describes interelectronic correlations.
• The functional can be adjusted to blend with dispersion corrections, avoiding double-counting.
• Preliminary calculations using the functional showed favorable agreement with reference interaction energies for non-covalently bound dimers, even with HF-like exchange.

Conclusions:

• The new meta-GGA functional offers a promising approach for accurate electronic structure calculations.
• The method provides a pathway to incorporate long-range dispersion effects reliably.
• This work advances the development of density functional theory for condensed matter and molecular systems.