issue contents

ISSN: 2052-2525

September 2014 issue

Highlighted illustration

editorial


link to html
The role of large-scale neutron and synchrotron facilities in the development of crystallographic research is discussed.

scientific commentaries


link to html
Some questions are hard to address, and equally hard to ignore. Recent work by C. Y. Su et al. [Jiang et al. (2014), IUCrJ, 305–317] concerns a highly challenging aspect of crystalline coordination polymers – trying to understand how they form.

link to html
The difficulties in defining the positions and thermal parameters for hydrogen atoms using X-ray diffraction data alone are discussed.

feature articles


link to html
The use of synchrotron radiation for experimental electron-density determination during the last decade is reviewed. Possible future directions of this field are examined.

link to html
Usually, semiconductors with a band gap Eg ≃ 3 eV or larger are called wide band gap materials. Their optical emission can span the whole of the visible spectrum, enabling the development of devices for solid-state lighting. In addition, a large Eg results in a high electrical breakthrough field, which is interesting for high-power electronics.

link to html
Patterson-function direct methods are chronologically reviewed and their applications to powder and electron diffraction are described.

research papers



link to html
The co-crystallization of cyclic and polymeric isomers in the same crystal in varying ratios with the skeleton frameworks packed in a geometrically compatible and energetically similar fashion gives a chance to rationalize ring-opening isomerization in a crystal growth process.

link to html
Relationships between the crystal structures of two polymorphs of sodium naproxen dihydrate and its monohydrate and anhydrate phases provide a basis to rationalize the observed transformation pathways in the sodium (S)-naproxen anhydrate–hydrate system.

link to html
Two new structural forms, a monomer and a swapped dimer, of the catalytic domain of an adenylyl cyclase from M. tuberculosis are reported.

link to html
An emulsion-based serial crystallographic technology has been developed, in which single crystals are grown in nanolitre-sized droplets inside an X-ray semi-transparent microfluidic chip exploiting a negative feedback mechanism. Diffraction data are measured, one crystal at a time, from a series of room-temperature crystals stored in the chip, and a 93% complete data set is obtained by merging single diffraction frames taken from different unoriented crystals to solve the structure of glucose isomerase to 2.1 Å.

link to html
The new automated iterative Hirshfeld atom refinement method is explained and validated through comparison of structural models of Gly–L-Ala obtained from synchrotron X-ray and neutron diffraction data at 12, 50, 150 and 295 K. Structural parameters involving hydrogen atoms are determined with comparable precision from both experiments and agree mostly to within two combined standard uncertainties.
Follow IUCrJ
Sign up for e-alerts
Follow IUCrJ on Twitter
Follow us on facebook
Sign up for RSS feeds