Electronic structure of kink and kink-antikink defects in polyacetylene

Journal Article · Fri Sep 15 00:00:00 EDT 1989 · Physical Review (Section) B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.40.6285· OSTI ID:5419335

Ye, L ^[1]; Freeman, A J ^[2]; Ellis, D E ^[3]

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1. Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (US) Department of Physics, Fudan University, Shanghai, People's Republic of China
2. Department of Physics and Astronomy and Materials Research Center, Northwestern University, Evanston, Illinois 60208 Center for Materials Science, Los Alamos National Laboratory, Albuquerque, New Mexico 87545
3. Department of Physics and Astronomy and Materials Research Center, Northwestern University, Evanston, Illinois 60208

The electronic energy levels and charge distribution associated with kink ({ital K}) and kink-antikink ({ital K}-{ital {bar K}}) defects in polyacetylene have been calculated with use of the first-principles local-density-functional theory. Finite-chain models with up to 40 carbon atoms were studied, in a self-consistent-field molecular-orbital approach. For the kink defect on {ital trans}-polyacetylene (PA), a half-filled midgap level was found, which corresponds to a neutral soliton having spin 1/2. Its formation energy was found to be 0.51 eV. Two defect levels were found for kink-antikink pair constructed on both the {ital trans}- and {ital cis}-PA chains. In the {ital trans} case, the formation energy is about 1.1 eV, which remains almost constant with increasing separation between {ital K} and {ital {bar K}}. The formation energy in the {ital cis} case increases monotonically with increasing separation and ranges from 0.3 eV for two intervening C atoms to 1.5 eV for 18 C atoms between {ital K} and {ital {bar K}}.

• DOE Contract Number: FG05-85ER75215
• OSTI ID: 5419335
• Journal Information: Physical Review (Section) B: Condensed Matter; (USA), Vol. 39:9; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
POLYACETYLENES
ELECTRONIC STRUCTURE
CHARGE DISTRIBUTION
CRYSTAL DEFECTS
DENSITY
ENERGY LEVELS
FORMATION FREE ENERGY
FUNCTIONALS
SELF-CONSISTENT FIELD
SOLITONS
CRYSTAL STRUCTURE
ENERGY
FREE ENERGY
FUNCTIONS
HYDROCARBONS
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
POLYENES
QUASI PARTICLES
THERMODYNAMIC PROPERTIES
360603* - Materials- Properties