Electronic Correlation Effects in Cyclic Polyenes and in Polyacetylene
Most papers written nowadays on polyacetylene [1,2] seem to accept as a well-established fact that the origin of the optical gap in trans-(CH)x is due to bond alternation arising from the Peierls instability. Yet a completely different explanation for the origin of the optical gap has been given by OVCHINNIKOV and coworkers , who suggested that the gap results from electronic correlations and not from bond alternation. Estimating the relevant physical parameters for polyacetylene from substances such as ethane, benzene, ethylene and graphite , they concluded that the electron-phonon coupling is much too small to produce a bond alternation large enough to explain the measured gap.
KeywordsGraphite Benzene Polyacetylene
Unable to display preview. Download preview PDF.
- 5.P. Horsch, submitted to Phys. Rev. BGoogle Scholar
- 8.I. Ohmine, M. Karplus, and K. Schulten, J. Chem. Phys. 68, 2298 (1978).Google Scholar
- 9.G. Stollhoff and P. Fulde, Z. Phys. B 26, 251 ( 1977 ); J. Chem. Phys. 73, 4548 (1980).Google Scholar
- 11.L. Salem, Molecular Orbital Theory of Conjugated Systems (W.A. Benjamin, New York, 1966 ) p. 514.Google Scholar
- 12.S. Strässler and L. Pietronero, Festkörperproblerne 21, 313 (1981).Google Scholar
- 14.K.R. Subbaswamy and M. Grabowski, submitted to Phys. Rev. B.Google Scholar