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Title: Accurate description of torsion potentials in conjugated polymers using density functionals with reduced self-interaction error

We investigate the torsion potentials in two prototypical π-conjugated polymers, polyacetylene and polydiacetylene, as a function of chain length using different flavors of density functional theory. Our study provides a quantitative analysis of the delocalization error in standard semilocal and hybrid density functionals and demonstrates how it can influence structural and thermodynamic properties. The delocalization error is quantified by evaluating the many-electron self-interaction error (MESIE) for fractional electron numbers, which allows us to establish a direct connection between the MESIE and the error in the torsion barriers. The use of non-empirically tuned long-range corrected hybrid functionals results in a very significant reduction of the MESIE and leads to an improved description of torsion barrier heights. In addition, we demonstrate how our analysis allows the determination of the effective conjugation length in polyacetylene and polydiacetylene chains.
Authors:
; ; ; ; ; ;  [1] ;  [1] ;  [2]
  1. School of Chemistry and Biochemistry and Center for Computational Molecular Science and Technology, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)
  2. (Germany)
Publication Date:
OSTI Identifier:
22255293
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; DENSITY FUNCTIONAL METHOD; FUNCTIONALS; HYBRIDIZATION; INTERACTIONS; POLYMERS; THERMODYNAMIC PROPERTIES; TORSION