A Density Functional with Spherical Atom Dispersion Terms.

Area of Science:

• Computational chemistry
• Quantum chemistry
• Materials science

Background:

• Most density functional theory (DFT) models exhibit spurious long-range interactions.
• Accurate modeling of weak interactions is crucial in chemistry and materials science.

Purpose of the Study:

• Introduce a new hybrid density functional, APF, designed to eliminate spurious long-range interactions.
• Develop and validate an empirical dispersion correction (APF-D) for improved weak interaction modeling.

Main Methods:

• Developed the APF hybrid density functional.
• Created the APF-D empirical dispersion model based on a spherical atom model (SAM).
• Trained APF-D using noble gas and hydrocarbon dimers, alongside atomic properties like ionization potential and polarizability.

Main Results:

• APF-D accurately describes potential energy surfaces for noble gas complexes and hydrocarbon dimers.
• The model reproduces relative conformational energies of organic molecules.
• Achieved accuracy comparable to CCSD(T)/aug-cc-pVTZ for weak interactions.

Conclusions:

• The APF-D model provides a robust and accurate method for describing weak interactions.
• Its performance in predicting geometries of hydrogen-bonded complexes is competitive with existing DFT and empirical dispersion models.