Long-range corrected density functional through the density matrix expansion based semilocal exchange hole.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Materials Science

Background:

• Density functional theory (DFT) is a cornerstone of modern computational chemistry.
• Accurate modeling of electron exchange is crucial for DFT accuracy.
• Range-separated hybrid functionals offer improved descriptions of electronic properties.

Purpose of the Study:

• To develop a novel long-range corrected (LRC) density functional.
• To incorporate an exchange hole derived from the density matrix expansion (DME).
• To improve the prediction of molecular properties using DFT.

Main Methods:

• Designed a new LRC density functional combining meta-generalized gradient approximation (mGGA) exchange with ab initio Hartree-Fock (HF) exchange.
• Utilized a density matrix expansion (DME) based exchange hole model.
• Employed range separation of the Coulomb interaction operator via the error function.
• Paired the functional with the Lee-Yang-Parr (LYP) correlation functional.

Main Results:

• The newly developed LRC functional demonstrates reasonable performance across various molecular property benchmarks.
• Accurate predictions were achieved for thermochemistry, non-covalent interactions, and chemical reaction barrier heights.
• The DME-based exchange hole satisfies key exact constraints, enhancing functional design.

Conclusions:

• The proposed LRC density functional offers a promising advancement in DFT.
• Combining DME-derived exchange with HF exchange provides a robust approach for LRC functionals.
• The functional's balanced performance makes it suitable for diverse chemical applications.