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Dispersion interactions in density-functional theory: an adiabatic-connection analysis
Marie D Strømsheim1, Naveen Kumar, Sonia Coriani
1Department of Chemistry, Centre for Theoretical and Computational Chemistry, University of Oslo, P.O. Box 1033, Blindern, Oslo N-0315, Norway.
The Journal of Chemical Physics
|November 25, 2011
Summary
This study analyzes dispersion interactions using density-functional theory and adiabatic connections. It highlights charge rearrangement as key to dispersion forces, crucial for understanding interactions between closed-shell systems.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Materials Science
Background:
- Dispersion interactions are crucial for describing molecular behavior.
- Density-functional theory (DFT) is a powerful tool for electronic structure calculations.
- Accurate treatment of dispersion forces remains a challenge in DFT.
Purpose of the Study:
- To analyze dispersion interaction energy and forces within DFT.
- To investigate the role of adiabatic connections in describing dispersion.
- To understand charge rearrangement effects in dispersion interactions.
Main Methods:
- Coupled-cluster singles-doubles-perturbative-triples (CCSD(T)) calculations for accurate densities.
- Construction of Kohn-Sham exchange-correlation potentials.
- Calculation of Hellmann-Feynman forces and comparison with analytic forces.
- Use of floating Gaussian basis functions and counterpoise correction.
Main Results:
- Accurate CCSD(T) densities validate Kohn-Sham potential construction.
- Charge rearrangement effects significantly contribute to dispersion forces.
- Adiabatic connection curves successfully recover exchange-correlation contributions.
- Dispersion interactions are confirmed as long-ranged and dynamically correlated.
Conclusions:
- DFT, through adiabatic connections, can accurately describe dispersion interactions.
- Understanding charge rearrangement is vital for improving dispersion force calculations.
- The study supports the use of range-separated hybrid functionals for dispersion.
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