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Structural manifestation of the delocalization error of density functional approximations: C(4N+2) rings and C(20) bowl, cage, and ring isomers.

dc.contributor.author Heaton-Burgess, Tim
dc.contributor.author Yang, Weitao
dc.coverage.spatial United States
dc.date.accessioned 2011-04-15T16:46:51Z
dc.date.issued 2010-06-21
dc.identifier http://www.ncbi.nlm.nih.gov/pubmed/20572695
dc.identifier.uri https://hdl.handle.net/10161/3322
dc.description.abstract The ground state structure of C(4N+2) rings is believed to exhibit a geometric transition from angle alternation (N < or = 2) to bond alternation (N > 2). All previous density functional theory (DFT) studies on these molecules have failed to reproduce this behavior by predicting either that the transition occurs at too large a ring size, or that the transition leads to a higher symmetry cumulene. Employing the recently proposed perspective of delocalization error within DFT we rationalize this failure of common density functional approximations (DFAs) and present calculations with the rCAM-B3LYP exchange-correlation functional that show an angle-to-bond-alternation transition between C(10) and C(14). The behavior exemplified here manifests itself more generally as the well known tendency of DFAs to bias toward delocalized electron distributions as favored by Huckel aromaticity, of which the C(4N+2) rings provide a quintessential example. Additional examples are the relative energies of the C(20) bowl, cage, and ring isomers; we show that the results from functionals with minimal delocalization error are in good agreement with CCSD(T) results, in contrast to other commonly used DFAs. An unbiased DFT treatment of electron delocalization is a key for reliable prediction of relative stability and hence the structures of complex molecules where many structure stabilization mechanisms exist.
dc.language eng
dc.language.iso en_US
dc.publisher AIP Publishing
dc.relation.ispartof J Chem Phys
dc.relation.isversionof 10.1063/1.3445266
dc.title Structural manifestation of the delocalization error of density functional approximations: C(4N+2) rings and C(20) bowl, cage, and ring isomers.
dc.type Journal article
duke.contributor.id Yang, Weitao|0110948
dc.description.version Version of Record
duke.date.pubdate 2010-6-21
duke.description.issue 23
duke.description.volume 132
dc.relation.journal Journal of Chemical Physics
pubs.author-url http://www.ncbi.nlm.nih.gov/pubmed/20572695
pubs.begin-page 234113
pubs.issue 23
pubs.organisational-group Chemistry
pubs.organisational-group Duke
pubs.organisational-group Physics
pubs.organisational-group Trinity College of Arts & Sciences
pubs.publication-status Published
pubs.volume 132
dc.identifier.eissn 1089-7690


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