title: Symmetry in electron diffractions from helical structures.
abstract: In this work, we elucidate the regular rule of the symmetry in electron diffraction patterns from helical structures. It is affected by the value of the dominating Bessel function orders for the layer lines and relative orientation of the samples with respect to the electron beam. For Single-Walled Carbon nanotubes (SWCNTs), we use analytic analysis and computer simulations to demonstrate that the 2mm symmetry of the electron diffraction may break down not only from an achiral SWCNT, but also from a chiral SWCNT. Also, the simulation work for B-DNA is presented to corroborate the theoretical analysis.
authors.affiliation: Beijing National Center for Electron Microscopy, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Jiong
authors.initials: J
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D004583:Electrons; D008958:Models, Molecular; D008968:Molecular Conformation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D012542:Scattering, Radiation
chemical_list: D037742:Nanotubes, Carbon; D004247:DNA