| Issue |
Europhys. Lett.
Volume 45, Number 2, January 1999
|
|
|---|---|---|
| Page(s) | 188 - 194 | |
| Section | Condensed matter: structure, thermal and mechanical properties | |
| DOI | https://doi.org/10.1209/epl/i1999-00145-8 | |
| Published online | 01 September 2002 | |
Crystal stability and optical properties of organic chain compounds
1
Department of Physics, Faculty of Science and Art,
University of Split Teslina 10, 21000 Split, Croatia
2
Department of Physics, Faculty of Science, University
of Zagreb POB 162, 10001 Zagreb, Croatia
Received:
29
July
1998
Accepted:
19
November
1998
The solution to the long-standing problem of the cohesion of organic chain compounds is proposed. We consider the tight-binding dielectric matrix with two electronic bands per chain, determine the corresponding hybridized collective modes, and show that three among them are considerably softened due to strong dipole-dipole and monopole-dipole interactions. By this we explain the unusual low-frequency optical activity of TTF-TCNQ, including the observed 10 meV anomaly. The softening of the modes also explains the cohesion of the mixed-stack lattice, the fractional charge transfer almost independent of the material, and the formation of the charged sheets in some compounds.
PACS: 61.50.Lt – Crystal binding; cohesive energy / 61.66.Hq – Organic compounds / 78.30.Jw – Organic compounds, polymers
© EDP Sciences, 1999
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.