Correcting for dispersion interaction and beyond in density functional theory through force matching.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Density Functional Theory (DFT) is a widely used quantum mechanical modeling method.
• Standard DFT functionals often struggle to accurately describe van der Waals interactions and hydrogen bonding.
• Post Hartree-Fock methods offer higher accuracy but are computationally expensive.

Purpose of the Study:

• To develop an improved DFT method using force matching.
• To accurately capture atomic forces and energy differences between DFT and high-accuracy quantum chemistry methods.
• To enhance the description of intermolecular and intramolecular interactions in molecular systems.

Main Methods:

• Employed the force matching method to design a supplemental potential.
• Incorporated two-body terms for dispersion and hydrogen bond corrections.
• Included one-body terms to refine intramolecular potential energy surfaces.
• Applied corrections to the Becke-Lee-Yang-Parr exchange-correlation functional for water.

Main Results:

• The enhanced DFT method significantly outperforms the standard DFT-D approach for water clusters.
• Achieved accuracy comparable to Quadratic Configuration Interaction with Singles and Doubles (QCISD) for relative cluster energies, atomic forces, and molecular structures.
• A Lennard-Jones term effectively corrected van der Waals interactions and exchange repulsion.
• One-body corrections notably reduced errors in binding energies and atomic forces.

Conclusions:

• The force matching approach provides a robust way to improve DFT accuracy.
• The developed method offers a computationally efficient alternative for high-accuracy predictions of molecular systems.
• This enhanced DFT method shows great promise for studying complex molecular interactions and properties.