MORPHOLOGIES AND RELATED ELECTRONIC-PROPERTIES OF CARBON NANOTUBES

The electronic structures of different morphologies of carbon nanotube s are investigated within either tight-binding or ab initio frameworks . After a brief description of the electronic properties of the ''perf ect'' rolled-up graphene sheet, nanotubes containing pentagon-heptagon pairs, tips (hemispherical caps), sp(3)-like lines responsible for po lygonization, multishell and solid-state packings (bundles) are studie d in order to point out the influence of such defects on the electroni c states of the ''perfect'' cylinders. Most of the time, a structural optimization was performed on the atomic topology, prior to the calcul ation of the electronic properties. Connections with experimental fact s are indicated as frequently as possible.