issue contents
November 2015 issue
editorial
Free
The field of crystallography, which has had a major impact on the sciences in the last 100 years, is continuing to expand scientific horizons as technical and conceptual boundaries are overcome. Structure–function–dynamics will become an integrated theme for many studies as will obtaining structures without the `benevolent tyranny' of crystals.
advances
research papers
DiffPy-CMI is a coherent computational framework designed for complex modeling in material structure solution.
foundations
research papers
In this paper a new construction of finite nested point sets with non-crystallographic symmetry is presented. This is based on the embedding of a non-crystallographic group G into the point group of a higher-dimensional lattice. The point sets are induced by the projection into a G-invariant subspace of orbits of lattice points under G-containing subgroups of . In the case of icosahedral symmetry, the point sets thus constructed provide structural constraints for the three-dimensional organization of viral capsids.
Tilings with a singular point are obtained by applying conformal maps on regular tilings of the Euclidean plane. The symmetries and color symmetries of these tilings are investigated.
New insights are provided into the uniqueness of the macromolecular crystallographic phase problem and its relationship to single particle imaging.
Entanglements of 3-periodic arrays of θ-graphs and regular two-dimensional honeycomb (hcb) nets are constructed from free tilings of the hyperbolic plane consisting of rare packings of regular trees mapped onto the P, D, G and H triply periodic minimal surfaces.
Based on the series expansion of the X-ray wavefield in eigenfunctions for solving a system of two linked integral equations, the grazing-incidence small-angle X-ray scattering from a random rough surface is considered.
addenda and errata
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international union of crystallography
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