issue contents
July 2015 issue
![Highlighted illustration](/a/issues/2015/04/00/graphics/coverill.gif)
Cover illustration: A new technique for the imaging of ferroelectric domains via resonant X-ray diffraction from a single Bragg reflection is described by Fabrizi et al. [Acta Cryst. (2015), A71, 361-367]. The domain contrast is achieved through the energy dependence of the resonant scattering around an atomic absorption edge.
advances
scientific commentaries
Free ![Open Access](/logos/open.png)
![Open Access](/logos/open.png)
A guide to the collection and processing of MicroED data invites X-ray crystallographers and electron microscopists to solve atomic structures from tiny protein crystals.
feature articles
Open
access
![Open Access](/logos/open.png)
The collection and processing of MicroED data are presented.
research papers
Open
access
![Open Access](/logos/open.png)
The identification and high-resolution mapping of the absolute crystallographic structure in multi-domain ferroelectric KTiOPO4 is achieved through a novel synchrotron X-ray diffraction method. On a single Bragg reflection, the intensity ratio in resonant diffraction below and above the Ti absorption K edge demonstrates a domain contrast up to a factor of ∼270, thus implementing a non-contact, non-destructive imaging technique with micrometre spatial resolution, applicable to samples of arbitrarily large dimensions.
foundations
research papers
Open
access
![Open Access](/logos/open.png)
A detailed and comprehensive theoretical description of X-ray diffraction moiré fringes for a bicrystal specimen is given on the basis of a calculation by plane-wave dynamical diffraction theory, where the effect of the Pendellösung intensity oscillation on the moiré pattern is explained in detail.
The number-theoretic concept of diaphony, as a measure of uniform distribution, is reviewed, highlighting its relation to crystallographic concepts like the largest interplanar spacing of a lattice, the structure-factor equation and the Patterson function.
This paper describes a method for unbiased peak extraction from atomic pair distribution functions using the information-theoretic Akaike information criterion.
A procedure for the approximation of viral capsids by icosahedral tilings is proposed and illustrated for a range of viruses from different families. The output tilings can be used as coarse-grained models of viral capsids, providing a basis for further mathematical modelling of their dynamic behaviour and assembly.
A closed-form method is developed to calculate correlation functions of arbitrarily stacked close-packed structures.
For investigation of the proton-disordered structure of clathrate hydrates, a new approach is presented which is based on topological crystallography.
Iterative projection algorithms are used to determine the structures of two tetrameric proteins starting with only a low-resolution envelope and the position of the non-crystallographic axes.
Temperature (20–300 K)- and energy-dependent phase shifts of resonant multiple-beam X-ray diffraction in germanium crystals, involving forbidden (002) and weak (222) reflections, are reported.
short communications
Some properties of the anisotropic displacement tensor have been revised. Complete tables for site-symmetry restrictions covering all special positions as listed in International Tables for Crystallography, Vol. A, are provided.
book reviews
Free ![Open Access](/logos/open.png)
![Open Access](/logos/open.png)