At LSI there is presently an activity concerning both the Semiempirical and the
Ab Initio study of Nanotubes.
In the small diameter Nanotubes (3,3), (5,0), (4,2) the LSI theory group has performed
Ab Initio calculations [Phys. Rev. Lett. 91, 046402 (2003),
Applied Physics A special number (2004)]
in the framework of Time-Dependent Density-Functional Theory, of
Optical Spectra and Electron Energy Loss Spectra (EELS).
Concerning peak positions and anisotropy effects, the results are in good agreement
with the experiment, provided that Crystal Local Field Effects (LFE)
(depolarization effects) are correctly taken into account.
Moreover, interactions between the tubes can strongly modify their absorption and
EELS.
The Nanotube Site