Characterization of spatial correlations in carbon nanotubes-modelling studies

The Debye equation has been used to compute the powder diffraction patterns of single- and multiwalled carbon nanotubes. By generating Cartesian coordinates of atoms the models of non-chiral and chiral nanotubes of any shape and size have been constructed. An efficient algorithm has been developed to calculate the kinematical diffraction profiles for the constructed models. The effect of curvature on the diffraction pattern has been examined by comparison of the model-based simulations for various nanotubes and a single graphene layer. The applicability of the numerical procedure is illustrated in the case of armchair, zig-zag and chiral nanotubes, both single and multiwalled. The results of the computer simulations are compared with X-ray diffraction data, recorded for multiwalled nanotubes and published recently [Szczygielska et al., Acta Phys. Polon. A 98 (2000) 611].