Incorrect dissociation behavior of radical ions in density functional calculations

Journal of Physical Chemistry A

Volumn 101, Issue 43, 1997, Pages 7923-7925

  Bally, Thomas ^a   Sastry, G Narahari ^a  

^a Institut de Chimie Physique de l'Université   (Switzerland)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000841587     PISSN: 10895639     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp972378y     Document Type: Article

References (11)

1. See, for example: Bally, T.; Truttmann, L.; Dai, S.; Williams, F. J. Am. Chem. Soc. 1995, 117, 7916.
2. Hrouda, V.; Roeselova, M.; Bally, T. J. Phys. Chem. A 1997, 101, 3925.
3. Woon, D. E.; Dunning, T. H. J. Chem. Phys. 1993, 98, 1358.
4. Raghavachari, K.; Trucks, G. W.; Pople, J. A.; Head-Gordon, M. Chem. Phys. Lett. 1989, 157, 479.
5. Carrington, A.; Pyne, C. H.; Knowles, P. J. J. Chem. Phys. 1995, 102, 5979.
6. Becke, A. D. Phys. Rev. A 1988, 39, 3098.
7. Becke, A. D. J. Chem. Phys. 1993, 98, 5648.
8. •+ we tested also other correlation functionals (Perdew, Perdew-Wang, Vosko, Wilk and Nusair) but these gave very similar results. Thus, the problem appears to be with the Becke exchange functional.
9. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Gill, P. M. W.; Johnson, B. G.; Robb, M. A.; Cheeseman, J. R.; Keith, T.; Petersson, G. A.; Montogomery, J. A; Raghavachari, K.; Al-Laham, M. A.; Zakrzewski, V. G.; Ortiz, J. V.; Foresman, J. B.; Cioslowski, J.; Stefanov, B. B.; Nanayakkara, A.; Challacombe, M.; Peng, C. Y.; Ayala, P. Y.; Chen, W.; Wong, M. W.; Andres, J. L.; Repogle, E. S.; Gomperts, R.; Martin, R. L.; Fox, D. J.; Binkley, J. S.; DeFrees, D. J.; Baker, J.; Stewart, J. P.; Head-Gordon, M.; Gonzales, M. C.; Pople, J. A. Gaussian Program, Version Gaussian 94, Rev. B1 and D4; Gaussian, Inc.: Pittsburgh, PA, 1995.
10. •+ even the HF density remains fully delocalized along the entire dissociation curve. At larger distances the localized and the delocalized "states" become degenerate.
11. 2 reaction coordinate. To effect this the system must lose all symmetry, which it does by localizing spin on charge on one of two double bonds (such as to be able to change the sign of the π-MO in the other one). We could locate the corresponding TS structure (which shows the expected properties) by all conventional ab initio methods (UHF, ROHF, UMP2, and QCISD) but not by BLYP or B3LYP because those methods refuse to effect the required localization of spin and charge. (Chemical Equation)