Whither structural biologists?

The scientific impact of accurate protein-structure prediction methods is being felt already, but how might they affect the work and careers of structural biologists?

Going beyond ensemble average angular cross-correlation analysis

Commentary is given on a paper [Lapkin et al. (2022). IUCrJ, 9, 425–438] reporting the application of angular X-ray cross-correlation analysis to the scattered intensity distribution measured in 3D reciprocal space from a single-crystalline sample.

Solving molecular compounds from powder diffraction data: are results always reliable?

Commentary is given on a paper [Schlesinger et al. (2022). IUCrJ, 9, 406–424.] reporting on ambiguous structure determination from powder data using four different structural models of 4,11-difluoroquinacridone with similar X-ray powder patterns.

Ambiguous structure determination from powder data: four different structural models of 4,11-di­fluoro­quinacridone with similar X-ray powder patterns, fit to the PDF, SSNMR and DFT-D

Four different structural models, which all fit the same X-ray powder pattern, were obtained in the structure determination of 4,11-di­fluoro­quinacridone (C₂₀H₁₀N₂O₂F₂) from unindexed X-ray powder data by a global fit. All models are chemically sensible, but differ in their lattice parameters, space groups, Z, Z′, molecular packing and hydrogen bond patterns, and were investigated by fit to the pair-distribution function, solid-state NMR and lattice-energy minimizations.

Angular X-ray cross-correlation analysis applied to the scattering data in 3D reciprocal space from a single crystal

The application of angular X-ray cross-correlation analysis to the scattered intensity distribution measured in 3D reciprocal space from a single-crystalline sample is proposed. This method provides a complementary view on the structure of the sample as well as defects present in this sample.

Reverse-engineering method for XPCS studies of non-equilibrium dynamics

A novel reverse engineering (RE) approach is presented based on particle-based heuristic simulations for the understanding of dynamics in non-equilibrium systems revealed by X-ray photon correlation spectroscopy measurements. The RE approach provides a direct connection between the experimental dynamic features and the key control parameters of the non-equilibrium process. This framework is also applicable to other related processes.

Semiconductive 2D arrays of pancake-bonded oligomers of partially charged TCNQ radicals

Extended arrays of pancake-bonded TCNQ radical anions lead to long-range spin interactions and conductivity in 2D.

Inhibition of Arenaviridae nucleoprotein exonuclease by bis­phosphonate

Virtual screening, molecular docking and molecular characterization of an Arenaviridae nucleoprotein exonuclease–inhibitor complex provided insight for structure-based drug design.

How to get maximum structure information from anisotropic displacement parameters obtained by three-dimensional electron diffraction: an experimental study on metal–organic frameworks

Structure models of metal–organic frameworks (MOFs) obtained after refining anisotropic displacement parameters (ADPs) against three-dimensional electron diffraction (3D ED) data can reveal important structural features, such as linker motion. We report strategies to obtain the maximum structure information from ADPs refined against 3D ED data.

A novel X-ray diffraction approach to assess the crystallinity of regenerated cellulose fibers

By using wide-angle X-ray scattering, contributions from amorphous and crystalline domains are detected separately in cellulose fibers, which enables an accurate determination of regenerated cellulose-fiber crystallinity.

Influence of modelling disorder on Hirshfeld atom refinement results of an organo-gold(I) compound

Incorporation of the description of disorder during Hirshfeld atom refinement influences the distribution of dynamic structure factors and, in consequence, also the contributions from electron correlation and relativistics.

Structure–property relations of a unique and systematic dataset of 19 isostructural multicomponent apremilast forms

A unique system of 19 isostructural apremilast multicomponent forms was explored and a correlation between the intrinsic dissolution rates of the new solid forms and the equilibrium solubility of their guest molecules has been discovered.

Symmetry of antiferroelectric crystals crystallized in polar point groups

AFE crystals could also crystallize in polar point groups. If the dipole moment is reversible along the anti-polar axis under an external electric field, the polar crystal is an AFE crystal.

Epitaxial intergrowths and local oxide relaxations in natural bixbyite Fe_2−xMn_xO₃

Different types of structural disorder in natural bixbyite are quantified from analysis of X-ray and neutron diffuse scattering