▎ 摘 要
Three different topological structures built on the basis of a graphene lattice are investigated. Clusters of the (3,6) type homeomorphic with the sphere, toroidal, and cylindrical carbon nanotubes are shown to have the same dispersion relation, inherited from the planar graphene lattice. The persistent currents in axially symmetric structures, their dependence on the size and geometry of the molecule, are also discussed.