Effect of dimensionality in polymeric fullerenes and single-wall nanotubes

We present new results for two examples where the dimensionality of a solid state system plays an important role. The systems under consideration are AC(60) (A = K, Rb, Cs) and single-wall nanotubes. In the first case we show that a spin-density-wave instability triggered by nearly perfect nesting of a 3-D Fermi-surface is responsible for the transition from a metallic to an insulating state. In the second case the analysis of the radial breathing mode as observed by Raman scattering from single-wall nanotubes is used to determine the types and radial distribution of the as prepared sample of tubes. (C) 1998 Elsevier Science B.V. All rights reserved.