X-ray lasers and serial crystallography

A summary is given of the achievements and opportunities which resulted from the first use of an X-ray laser for serial crystallography and related methods in 2009.

Powder to become crystal clear

A simulation by Zhang et al. [IUCrJ (2015), 2, 322–326] has demonstrated that utilizing serial crystallography may turn one-dimensional powder diffraction from multiphase polycrystalline samples into three-dimensional single-crystal diffraction patterns.

Operational properties of fluctuation X-ray scattering data

X-ray scattering images collected on timescales shorter than rotation diffusion times using a (partially) coherent beam result in a significant increase in information content in the scattered data. In this communication, an intuitive view of the nature of fluctuation scattering data and their properties is provided, the effect of such data on the derived structural models is highlighted, and generalizations of the Guinier and Porod laws that can ultimately be used to plan experiments and assess the quality of experimental data are presented.

Second harmonic generation from the `centrosymmetric' crystals

Based on the observation of second harmonic generation (SHG), the solid state structure of a Zn(II) complex has been reinterpreted in terms of the non-centrosymmetric space group Cc, with residual polarity arising from unequal antiparallel packing. Temperature-dependent measurements showed that the highest SHG has been observed at 50 K and the lowest at 170 K.

SFX analysis of non-biological polycrystalline samples

A serial femtosecond crystallography based method has been proposed, which enables simultaneous X-ray phase identification and structure solution for multiphase polycrystalline samples. Test results from simulating calculations are encouraging.

Likelihood of atom–atom contacts in crystal structures of halogenated organic compounds

The analysis, based on Hirshfeld surfaces, reveals which atoms are the preferred partners of halogens in crystal packing contacts.

Do carboximide–carboxylic acid combinations form co-crystals? The role of hydroxyl substitution on the formation of co-crystals and eutectics

Cocrystallization of cyclic imides with benzoic acid and some of its hydroxyl analogues resulted in cocrystals and eutectics in a mutually exclusive manner depending on the presence or absence and position of the hydroxyl group and consequent supramolecular effect for different combinations.

A posteriori determination of the useful data range for small-angle scattering experiments on dilute monodisperse systems

The useful experimental data range for solution small-angle scattering is assessed through the number of meaningful Shannon channels that can be determined from a given data set, and a robust algorithm is provided to determine this range automatically.

Serial snapshot crystallography for materials science with SwissFEL

We have mimicked the 4%-energy-bandpass mode of the SwissFEL beam at a synchrotron facility, collected snapshots of randomly oriented multi-crystal samples, and developed a methodology to index and process such non-monochromatic data for materials science applications.

X-ray imaging detectors for synchrotron and XFEL sources

Hybrid and monolithic detectors for X-ray imaging are reviewed.