Application of standard DFT theory for nonbonded interactions in soft matter: Prototype study of poly-para-phenylene
✍ Scribed by Marcelo Alves-Santos; Liliana Y. A. Dávila; Helena M. Petrilli; Rodrigo B. Capaz; Marília J. Caldas
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 228 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0192-8651
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✦ Synopsis
Abstract
We present a detailed analysis of the application of density functional theory (DFT) methods to the study of structural properties of molecular and supramolecular systems, using as a paradigmatic example three para‐phenylene‐based systems: isolated biphenyl, single chain poly‐para‐phenylene, and crystalline biphenyl. We use different functionals for the exchange correlation potential, the local density (LDA), and generalized gradient approximations (GGA), and also different basis sets expansions, localized, plane waves (PW), and mixed (localized plus PW), within the reciprocal space formulation for the hamiltonian. We find that regardless of the choice of basis functions, the GGA calculations yield larger interring distances and torsion angles than LDA. For the same XC approximation, the agreement between calculations with different basis functions lies within 1% (LDA) or 0.5% (GGA) for distances, and while PW and mixed basis calculations agree within 1° for torsion angles, the localized basis results show larger angles by ≃ 8° and a nonmonotonic dependence on basis size, with differences within 6°. The most prominent features, namely the torsion between rings for isolated molecule and infinite chain, and planarity for the molecule in crystalline environment, are well reproduced by all DFT calculations. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 217–227, 2006