Atomic level three-dimensional structure of individual particles with XFELs

Progress in single-particle three-dimensional imaging is discussed, with advances in both data-collection and data-handling techniques described.

De novo protein structure determination by heavy-atom soaking in lipidic cubic phase and SIRAS phasing using serial synchrotron crystallography

Lipid cubic phase supplemented with mercury was used to create a heavy-atom derivative of microcrystals for direct SIRAS phasing using serial millisecond crystallography.

Considerations for three-dimensional image reconstruction from experimental data in coherent diffractive imaging

A three-dimensional reconstruction of the Melbournevirus affected by a strong artifact in the center of the particle is presented. Using simulations, the artifact was found to be probably caused by background scattering, while particle size and pulse-energy variation did not affect the quality of the reconstruction. Possible ways to minimize such problems in the future are suggested.

Do the basic crystal chemistry principles agree with a plethora of recent quantum chemistry data?

Electron descriptors such as bond order and electron density at the bond critical point are key quantities in establishing the characterization of chemical bonding. This paper analyzes a plethora of quantum chemistry data available in the literature to confirm exponential correlations between these electron descriptors and the interatomic distances for any type of chemical bond. This is particularly relevant for extending the crystal chemistry bond order conservation principle to systems with delocalized electrons.

Solving protein structure from sparse serial microcrystal diffraction data at a storage-ring synchrotron source

This work develops an analysis approach that can solve protein structures from data frames whose signals are too weak to be indexed. The approach is demonstrated on a serial microcrystallography data set collected at a storage-ring synchrotron source.

Double role of metalloporphyrins in catalytic bioinspired supramolecular metal–organic frameworks (SMOFs)

Bioinspired metalloporphyrin-based supramolecular MOFs have been successfully tested for heterogeneous catalytic applications.

Controlled usage of H/D exchange to circumvent concomitant polymorphs of ROY

Deuteration of ROY at its amine function allowed the circumvention of concomitant polymorphs and produced exclusively the yellow Y polymorph of d₁-ROY.

Rapid sample delivery for megahertz serial crystallography at X-ray FELs

Sample delivery is a major challenge to performing serial crystallography experiments at upcoming high-repetition-rate X-ray free-electron lasers. The feasibility of using gas-driven liquid jets for this purpose at the FLASH facility in Hamburg has been studied.

Homology-based loop modeling yields more complete crystallographic protein structures

Thousands of regions missing from existing protein structure models are completed using new methods based on homology.

The hydrocarbon-bearing clathrasil chibaite and its host–guest structure at low temperature

The crystal structure of chibaite (a natural clathrasil with an MTN-type framework structure) and its structural evolution with decreasing temperature from space-group symmetry to A2/n were investigated with single-crystal X-ray diffraction and Raman spectroscopy.

Twist and turn: a revised structural view on the unpaired bubble of class II CPD photolyase in complex with damaged DNA

Co-crystallization with the natural, phosphodiester-linked substrate combined with exhaustive computational analysis reveals how photolyases stabilize and lock the DNA unpaired bubble resulting from cyclobutane pyrimidine dimer binding and subsequent flip-out.

Structural basis for light control of cell development revealed by crystal structures of a myxobacterial phytochrome

Light control of cell development is revealed by phytochrome structures of Myxobacteria.

Bond orders for intermolecular interactions in crystals: charge transfer, ionicity and the effect on intramolecular bonds

Roby–Gould bond orders for intermolecular interactions such as hydrogen bonds, halogen bonds and chalcogen bonds in molecular crystals have been explored. Bond-order values place these interactions on a scale representing their relative strengths, in conjunction with a chemist's notion of bonds.

Exploring the simultaneous σ-hole/π-hole bonding characteristics of a Br⋯π interaction in an ebselen derivative via experimental and theoretical electron-density analysis

Experimental and theoretical multipolar charge-density analyses of a unique short Br⋯π interaction in an ebselen derivative have been performed. They establish unequivocally the concomitant existence of the characteristics of σ-hole and π-hole bonding in the same interaction.

Comments on `Hydrogen bonds in crystalline D-alanine: diffraction and spectroscopic evidence for differences between enantiomers'

The recent claim of structural differences between alanine enantiomers in the solid state is critically discussed.

Response to comment on `Hydrogen bonds in crystalline D-alanine: diffraction and spectroscopic evidence for differences between enantiomers'

A response is given to comments by Bürgi & Macchi [IUCrJ (2018), 5, 654–657] about Belo et al. [IUCrJ (2018), 5, 6–12.].