Abstract
Predicting accurate bond-length alternations (BLAs) in long conjugated molecular chains has been a major challenge for electronic-structure theory for many decades. While Hartree-Fock (HF) overestimates BLA significantly, second-order perturbation theory and commonly used density functional theory (DFT) approaches typically underestimate it. Here, we discuss how this failure is related to the many-electron self-interaction error (MSIE), which is inherent to both HF and DFT approaches. We use tuned long-range corrected hybrids to minimize the MSIE for a series of polyenes. The key result is that the minimization of the MSIE alone does not yield accurate BLAs. On the other hand, if the range-separation parameter is tuned to yield accurate BLAs, we obtain a significant MSIE that grows with chain length. Our findings demonstrate that reducing the MSIE is one but not the only important aspect necessary to obtain accurate BLAs from density functional theory.
| Original language | English (US) |
|---|---|
| Article number | 124305 |
| Journal | JOURNAL OF CHEMICAL PHYSICS |
| Volume | 137 |
| Issue number | 12 |
| DOIs | |
| State | Published - Sep 28 2012 |
| Externally published | Yes |
Bibliographical note
Funding Information:The Center for Computational Molecular Science and Technology is funded through a National Science Foundation (NSF) CRIF award (Grant No. CHE-0946869) and by the Georgia Institute of Technology. This work was partly supported by the AFOSR through the COMAS MURI program (Agreement No. FA9550-10-1-0558). T.K. thanks the AvH Foundation for financial support through the Feodor-Lynen program. R.P. thanks the U.S. Department of Energy for funding through the Computational Science Graduate Fellowship Program (DE-FG02-97ER25308). C.D.S. acknowledges support from the US National Science Foundation (Grant No. CHE-1011360).
ASJC Scopus subject areas
- General Physics and Astronomy
- Physical and Theoretical Chemistry