forthcoming articles

We describe 3-periodic, vertex- and arc-transitive, polycatenated structures formed from rings, polyhedra and rods. There are infinite families of infinite structures, and this report is restricted to those structures with units linked to three or six others.

The quasiperiodic nature of moiré patterns in homophase twisted bilayers is analyzed to understand the underlying basic periodicities and symmetries of homophase twisted bilayers built on any 2D structure.

Pressure-induced structural strain in (R)-3-quinuclidinol crystals is analysed over different pressure ranges[under pressure] and com­pared with structural strain on cooling.

The methodology proposed combines the DFT calculations and photoelasticity caused by uniaxial compression of the crystal lattice, with particular emphasis on its anisotropy. It can be considered as part of optical engineering aimed at preliminary assessment of the photoelastic properties of crystal materials, thus assisting in their selection for synthesis and relevant applications.

Several Li⁺/Fe³⁺-doped Pbca orthoenstatite and Pbcn protoenstatite crystals were characterized revealing that varying levels of doping preferentially affect the py­rox­ene topologies.

Electron density distribution in bis(guanidinium) disodium hypodiphosphate heptahydrate, (CH₆N₃)₂Na₂(P₂O₆)·7H₂O, is reported.

A rare complex incommensurate magnetic structure, an amplitude-modulated structure which itself is modulated, was determined in the Ho-based i-MAX phase (Mo_2/3Ho_1/3)₂GaC. It represents a particularly distinctive case of a 2-k magnetic structure with no symmetry relation between the propagation vectors.

The patterns of microbial crystallization are controlled by the chemical composition of biofilms associated with environmental exposure and the activity of microorganisms. The nutrition of microorganisms changes the oxalic acid and extracellular polymer substance content in the products of microbial metabolism, which significantly affects the medium pH promoting either the oxalate or carbonate crystallization.

The monoprotonated species of 2-amino­malonyl difluoride, [C₃H₄F₂NO₂][H₂F₃], is particularly inter­esting for the protonation in superacidic media, as well as in Lewis acidic media, due to its two acyl fluoride moieties. The crystal structure is the first single-crystal X-ray diffraction measurement of this com­pound or its salts.

Fast readout event-based electron counting (EBEC) is a promising detection strategy to determine accurate ab initio structures of beam-sensitive small mol­ecules by MicroED. A fast EBEC approach enhances the dynamic range of MicroED data by limiting the likelihood of coincidence loss (CL) – the undercounting of electrons due to their spatially and temporally unresolved arrival on a direct electron detector. As implemented by new counting detectors, fast EBEC allows structure-worthy data sets to be captured from individual small-mol­ecule crystals in under a minute.

Crystal structures of ACDC domains derived from distinct Plasmodium ApiAP2 proteins reveal a conserved, unique noncanonical four-helix bundle architecture.

The crystal structures of three salts of tri­phenyl­sulfonium ion are reported, namely, tri­phenyl­sulfonium triiodide (I), tri­phenyl­sulfonium perchorate (II), tri­phenyl­sulfonium hexa­fluoro­phosphate (III).

The asymmetric unit consists of two independent mol­ecules of the substituted imidazolone having different conformations, and one mol­ecule of solvent DMF. The two imidazolone mol­ecules are linked by N—H⋯N and C—H⋯O hydrogen bonds and the DMF is joined to one of these by a N—H⋯O hydrogen bond. Additional N—H⋯N and C—H⋯O hydrogen bonds link these groups into corrugated layers parallel to the (101) plane with the layers joined by C—H⋯π (ring) inter­actions.

In the crystal structure of the title compound, the Ce^III cations are ninefold coordinated and linked into chains via the acetate anions and are further connected into layers by the sulfate dianions.

The title compounds exhibit Ir—C and Ir—N bond lengths typical of cyclo­metallated iridium compounds with phenyl­pyridine ligands. Methyl­ation of the phenanthroline ligand leads to longer Ir—N bond lengths compared to the unmethyl­ated analog.

CryoCrane is a GUI which allows rapid analysis of cryo-EM screening data and supervision of data collections.

Contaminating proteins from the expression source may inadvertently crystallize instead of the target protein of interest. Two novel crystal forms of E. coli carbonic anhydrase 2, as well as a high-resolution (1.43 Å) structure of the enzyme, are reported.

tRNA 2-selenouridine synthase (SelU) produces a 5-substituted 2-selenouridine at the tRNA wobble position, which can fine-tune translation. Crystals of the SelU–tRNA complex were obtained and the initial structure was determined at 3.10 Å resolution.

The forensic field requires versatile equipment for non-destructive characterization, analysis and inspection of 2D and 3D objects. The robotic scanner introduced here allows transmission X-ray imaging and mapping of individual photons with high-sensitivity and -resolution detectors. The broad capabilities of X-ray diffraction (XRD) imaging are now being complemented by X-ray fluorescence point analysis and mapping, multispectral macro imaging, and multispectral XRD analysis.

A computational and experimental investigation of integral X-ray diffuse scattering near Bragg reflections with a wide-open detector is presented for the case of small circular irradiation-induced dislocation loops in metals. The large wavevector asymptotic power-law falloff for such loops is determined computationally and incorporated into numerical and analytical integral X-ray diffuse scattering cross-section calculations. These calculations are shown to enable the experimental determination of the size distribution and concentrations of irradiation-induced dislocation loops in single-crystalline tungsten.

Microcrystal electron diffraction (microED) was used to determine the crystal structure of a recently synthesized metal–organic framework (MOF) from powder crystallites. The structural descriptions of two other MOFs by microED are compared with results previously published using X-ray powder diffraction supported by density functional theory calculations.

The proposed Python library and graphical user interface (GUI) provide an open-source solution for crystal chemical analysis of both user data and published datasets. A user-friendly GUI ensures availability of the basic library features for crystallographers without programming skills, whereas more advanced use is possible for those familiar with Python.

This work introduces the first direct comparison of contrast arising from dislocations using dark-field X-ray microscopy (DFXM) and the established method of transmission electron microscopy (TEM). We propose a method to directly measure the Burgers vector of a dislocation based on the symmetry with which DFXM scans across a rocking curve for a given diffraction peak.

This work provides practical information on the conventional top dusted sample preparation method and the top dusted adhesive tape sample preparation method. For the top dusted adhesive tape method, tapes with matte acetate or polyvinyl chloride backing are recommended as they cause a comparatively low background signal without high-intensity reflections.

To assess the performance of a double-crystal Laue-case monochromator, this study utilizes crystal simulation which integrates two diffraction profile calculation methods, two crystal depiction approaches and dual thermal distortion treatments. The thermal assessment effectively captures interior lattice plane distortions, enabling the simulation of crystal conditions closely matching actual scenarios.

A demonstration is given of the use of discrete and low-dimensional structure models within the periodic formalism of conventional Rietveld refinement software for the calculation of total scattering patterns.

This article describes a new phase identification algorithm called poly intended for spotty selected-area electron diffraction patterns collected from polymorphic nanomaterials. We have developed this new approach to determine the predominant high-pressure phases produced in laser-shock-affected regions of silicon. In this study, applying this algorithm allowed us to reliably identify two new t32-Si and t32*-Si phases and indicate their relaxation time in other metastable high-pressure silicon phases.

This controlled radiation damage study at different temperatures allows to refine approaches to measure radiation damage free/limited spectra from redox senstiive metalloenzymes and metal complexes in the soft X-ray regime at synchrotrons.

A method for compensating for the source drift of a free-electron laser beamline by adjusting the C_ff value of a grating monochromator is introduced.

A timing control system to stabilize the long-term timing drift between X-ray free-electron laser (XFEL) and optical laser pulses has been developed by utilizing an out-of-loop balanced optical-microwave phase detector and an arrival-timing monitor. The timing jitter and drift between the XFEL and the optical laser pulses have been reduced to less than 50 fs (RMS) over ∼49 h.

We present the development of a novel fixed-target flip-holder for synchrotron serial crystallography. This holder simplifies the sample handling process, reduces dehydration risks, and enables efficient crystallography experiments with minimal sample consumption, demonstrated through successful lysozyme crystal structure determination at room temperature.

This study employs quantum crystallography to elucidate the selectivity of NSAIDs, including ibuprofen, flurbiprofen, meloxicam, and celecoxib, for COX-1 and COX-2 enzymes by analyzing binding energy and electrostatic interactions. The findings reveal key structural determinants of NSAID selectivity, providing valuable insights for the rational design of safer and more effective anti-inflammatory drugs.

We used the Bragg coherence diffraction imaging (BCDI) method at the Coherent Scattering and Imaging (CSI) endstation of the Shanghai Soft X-ray Free Electron Laser Facility (SXFEL) to characterize colloidal crystals. This method was successfully reproduced the static shape of crystals and observed the defect structure of colloidal samples.

This is the first instance completed by the crystallographic fragment-screening platform of the Shanghai Synchrotron Radiation Facility (SSRF) in China. 800 fragments were screened and 91 compounds were identified to bind at eight different sites.

Here we identify and characterize the warping of molecular crystal lattices induced by electron beam exposure during microcrystal electron diffraction (MicroED/3DED) data collection. We find changes to consensus crystal lattice orientation that are often dramatic, and appear ubiquitous in small organic molecule crystals. This evidence highlights the relevance of crystal bending or warping as a consequence of radiation-induced damage on molecular specimens, and points to it as a fundamental source of error in MicroED/3DED data collection and structure determination.

Differences in the electronic structures of Cu(I) and Cu(II) coordination compounds with the same ligand as the model structures of `blue copper proteins' were studied.

A novel statistical metric for 2D template matching (2DTM), the 2DTM p-value, has been developed to improve the detection of targets in cryo-EM images under various imaging and sample conditions, particularly for smaller and aspherical targets.