Acta Crystallographica Section A

Foundations of Crystallography

Volume 59, Part 2 (March 2003)

research papers

Acta Cryst. (2003). A59, 168-171 [ doi:10.1107/S0108767303002186 ]

Structures of a hollow filamentary conical helix

F.-F. Xu and Y. Bando

Abstract: A hollow conical helix (HCH) of graphitic materials broadens the conical configuration by introduction of wrapping about 120° symmetry positions in addition to the traditional rotation about 60° symmetry sites. Complete structural models are established for a HCH and examined taking into account the rotation mode, coincidence site lattice (CSL), disclination angle and packing pattern. Combined with experimental observations, it is revealed that the size of the CSL, hence the density of the coincidence lattice sites, dominates the overlap configuration of a conical helix.

Keywords: conical helix; graphitic materials.