Communication: Correct charge transfer in CT complexes from the Becke'05 density functional.
Axel D Becke1, Stephen G Dale1, Erin R Johnson1
1Department of Chemistry, Dalhousie University, 6274 Coburg Road, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2, Canada.
The Journal of Chemical Physics
|June 10, 2018
Summary
Density-functional theory (DFT) methods often err in charge-transfer (CT) complex calculations. The Becke'05 (B05) functional accurately predicts charge transfer, potentially solving the long-standing delocalization error in DFT.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Materials Science
Background:
- Generalized gradient approximation (GGA) density functionals and hybrids with low exact-exchange fractions exhibit significant errors in charge-transfer (CT) complex properties.
- This
- delocalization
- error also affects CT excitation energy computations, remaining an unresolved issue in density-functional theory (DFT).
Purpose of the Study:
- To investigate the performance of the 100% exact-exchange Becke'05 (B05) density functional for charge-transfer (CT) complexes.
- To assess B05's potential to resolve the delocalization error in DFT.
Main Methods:
- Utilized the Becke'05 (B05) density functional, a 100% exact-exchange-based functional.
- Employed a variational approach, consistent with previous work on B05min dipole moments.
Main Results:
- B05 accurately predicts charge transfer in classic CT complexes, including electron donors like NH3, C2H4, HCN, and C2H2, and acceptors like F2 and Cl2.
- The results indicate excellent charge transfer predictions, addressing the known limitations of other DFT functionals.
Conclusions:
- The Becke'05 (B05) functional shows promise as a solution to the delocalization error in density-functional theory.
- B05 is demonstrated to be an accurate DFT for thermochemistry and CT complex properties.
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