Non-covalent interactions and thermochemistry using XDM-corrected hybrid and range-separated hybrid density...

Area of Science:

• Quantum Chemistry
• Computational Materials Science

Background:

• Accurate modeling of non-covalent interactions is crucial for predicting molecular behavior.
• Traditional density functionals struggle with the long-range behavior of exchange and dispersion forces.

Purpose of the Study:

• To enhance density functionals by incorporating the exchange-hole dipole-moment (XDM) model for dispersion.
• To evaluate the performance of XDM-corrected functionals across various chemical and physical benchmarks.

Main Methods:

• Combining the XDM model with semilocal, hybrid, and range-separated hybrid functionals.
• Testing against benchmarks for non-covalent interactions, conformer ranking, thermochemistry, and kinetics.

Main Results:

• Functionals with accurate -1/r exchange tails show superior performance for weak interactions.
• XDM correction significantly improves the accuracy of functionals like BLYP, B3LYP, and LC-ωPBE.
• PW86PBE-XDM demonstrated improved performance across most tested properties.

Conclusions:

• Balancing long-range exchange and dispersion via XDM is vital for accurate descriptions of molecular interactions.
• LC-ωPBE-XDM is proposed as a highly accurate functional for both hard and soft matter applications.