100 years of crystallography: the IUCr launches a comprehensive open-access journal, IUCrJ

IUCrJ is a fully open-access journal that aims to publish high-quality structural science papers. It has been launched for the International Year of Crystallography (IYCr2014).

Phasing tiny crystals

For tiny crystals, their diffraction intensities at and between the Bragg peaks become measurable due to the limited number of the unit cells, which can in principle be used to directly phase the crystal structures.

Type II halogen···halogen contacts are halogen bonds

Cl/Br/I alternative substitutions in a series of dihalophenols indicate that type I and type II halogen···halogen contacts have different chemical nature. Only the latter ones qualify as true halogen bonds, according to the recent IUPAC definition.

Crystal landscape in the orcinol:4,4′-bi­pyridine system: synthon modularity, polymorphism and transferability of multipole charge density parameters

The role of the supramolecular synthon as the operational structural unit in the late stages of the crystallization event is highlighted with reference to polymorphs and pseudopolymorphs in the orcinol–bipyridine cocrystal system.

Ab-initio phasing using nanocrystal shape transforms with incomplete unit cells

The shape transforms of nanocrystals with incomplete unit cells are studied using computer simulations. Structure-factor phases can be retrieved from the molecular transforms after removing the modulating shape transform terms.

Structural insights into WcbI, a novel polysaccharide-biosynthesis enzyme

The structure of WcbI, a protein essential to the virulence of B. pseudomallei, reveals that this protein has a novel fold. WcbI binds strongly to coenzyme A, but appears to require an unidentified partner protein for its putative acetyltransferase function.

Analysis of the structural continuity in twinned crystals in terms of pseudo-eigensymmetry of crystallographic orbits

A general approach to the analysis of structural continuity in twins is presented and applied to the known twins in melilite.

Halogen bonds in some dihalogenated phenols: applications to crystal engineering

The preference of Br to form type II contacts over type I is explored by various techniques. The mechanical properties of some dihalogenated phenols are correlated with their structures.

On the correlation between hydrogen bonding and melting points in the inositols

13 new phases of the inositols, 1,2,3,4,5,6-hexahydroxycyclohexane, were found. Crystal structure determinations and thermal analyses reveal a very complex picture of phases, rotator phases and phase transitions.

Do we see what we should see? Describing non-covalent interactions in protein structures including precision

The presentation of non-covalent interactions in protein X-ray crystal structures needs to routinely include their atomic precision, as detailed here; a user knowledge base for these precisions with examples is also offered. Cases are also indicated where the need for such a description of precision is a natural extension, such as those involving metalloproteins and the protonation states of ionisable amino acids. This study is also relevant to protein three-dimensional structure molecular-graphics software.