forthcoming articles

The program GraphT–T (V1.0Beta) has been developed to embed graphical representations of observed and hypothetical chains of (SiO₄)⁴⁻ tetrahedra into 2D and 3D Euclidean space.

Following the previous work [Biran & Gorfman (2024). Acta Cryst. A80, 112–128], all the possibilities for permissible (mismatch-free) walls between monoclinic domains of pseudocubic ferroelectric perovskites of M_C type are analyzed. The study yields analytical expressions for the orientation of such walls, the orientation relationship between the lattice vectors and for the separation between Bragg peaks diffracted from matched domains.

It is shown that all possible topologically distinct chain graphs of tetrahedra may be embedded into 3D Euclidean space. In minerals, separations between linked T cations are 3.06 (15) Å and between unlinked T cations are >3.71 Å, and these distances constrain the ability of embedded chain graphs to occur as structural entities in crystals. Software (GraphT-T) allows this embedding to be tested for stereochemical viability.

Recent methodological developments and their applications in quantum crystallography are reviewed, also with an overlook towards near-future advancements in this research field.

The essay introduces a novel dual-detection fluorescent sensing platform, Eu@nZCP, for highly selective sensing of mercury (Hg) and L-Cysteine (L-Cys) in aqueous media. The platform is based on a new nanoscale Zn^II coordination polymer (nZCP) synthesized using ultrasound irradiations, incorporating Eu³⁺ ions into its host lattice (Eu@nZCP). The analog single crystal (ZCP) was also prepared and using SXRD, its structure determined as a 2D porous CP with distinctive 6³ network.

Density-functional calculations using numerical atomic orbitals and the exchange-hole dipole moment dispersion model were applied to the energy ranking stage of the [for the]seventh crystal structure prediction blind test. This methodology gave successful predictions of the experimentally isolated polymorphs as being low in energy for three of the compounds considered, and for one additional compound upon inclusion of a vibrational free-energy correction.

A novel ternary oxynitride SnGe₄N₄O₄ has been synthesized under high-pressure high-temperature conditions in a large-volume press. Its crystal structure (P6₃mc) and the crystal structure of a 6R polytype (R3m) were determined by three-dimensional electron diffraction from submicrometer-sized crystals.

Robustness of supramolecular synthons in the lamotrigine solvates and hydrate has been investigated in order to be applied for the lamotrigine cocrystals design.

The presence of three unique trimeric supramolecular motifs in the crystal structures of dihalogenated 1,2,4-triazole derivatives is explored.

A design is tested for a polymorph search algorithm relevant for enhanced sampling of crystal structures based on the relation between internal molecular structure variables and corresponding crystal polymorphs as representative of the inherent vapor to crystal transitions that exist in nature. Molecules are represented as extended variables within a thermal reservoir. Unit-cell variables are generated using pseudo-random sampling incorporating a harmonic coupling to extended variables.

Three heterometallic coordination polymers (CPs) have been synthesized and characterized, employing trimesic acid as the organic linker. Upon com­plexation with mixed metal ions, the doubly and fully deprotonated forms of the ligand exhibit distinct coordination modes, resulting in distinct structural dimensionalities of the final networks. One of the CPs is a promising candidate for targeted investigation as a luminescent sensor for the recognition and detection of small organic mol­ecules.

The crystal structures of three mixed-valence copper cyanide polymers with similar polymeric CuCN networks are described, together with the results of electron spin resonance and thermogravimetric analyses.

The diethyl N,N′-(1,3-phenyl­ene)dicarbamate–theophylline (1–TEO) com­plex was obtained by mechanochemistry involving the conformational change of one of the ethyl carbamate groups of 1 from the endo conformation to the exo conformation to allow the formation of inter­molecular inter­actions.

Crystallization of 3,3′,5,5′-tetra­nitro-4,4′-bi­pyrazole obeys Ostwald's rule of stages and features the emergence of metastable highly hydrated phases prior to the formation of the stable monohydrate.

A new polymorphic form of the caffeine–citric acid cocrystal, solved by powder X-ray diffraction thanks to synchrotron experiments, was com­pared with the already known forms. An analysis of the hydrogen bonding indicates that the cocrystal obtained here is less stable than the co­crystals already identified in the literature.

Thee structure of ketohexokinase C in complex with a natural substrate and product ADP mimicking the Michaelis complex is reported and a comparison with other structures with and without ligands shows that it undergoes a conformational change that places the enzyme into a catalytically competent form. These findings will be of interest to those in the area of enzymology, enzyme structure–function and drug discovery.

Crystallographic fragment screening of the bacterial target Listeria monocytogenes CdaA is reported.

This review covers the symptoms of radiation damage in macromolecular crystallography, how to avoid accruing radiation damage during data collection and how to identify and correct for radiation-damage artefacts in a solved structure.

Through the analysis of more than 115 000 metal-binding sites in metalloproteins, experimentalists are offered useful reference data that improve the understanding of metal-binding interactions and protein coordination. Carboxylate coordination, which is common for a variety of metals, is especially highlighted.

The title compound, C₁₂H₁₀N₂O₃, was obtained by the de­acetyl­ation reaction of 1-(6-amino-5-nitro­naphthalen-2-yl)ethanone in a concentrated sulfuric acid methanol solution. The mol­ecule comprises a naphthalene ring system bearing an acetyl, amino and nitro groups. In the crystal, the mol­ecules are assembled into a two-dimensional network by N⋯H/H⋯N and O⋯H/H⋯O hydrogen-bonding inter­actions. n–π and π–π* stacking inter­actions are the dominant inter­actions in the three-dimensional crystal packing.

The title compounds are two calix[4]arenes with a pinched cone conformation and one with a 1,3-alternate conformation.

In the complex [Pt(C₉H₆NO)Cl(C₂H₄)], ethyl­ene coordinates with Pt^II in the η² manner and in the trans position compared to the coordinating N atom. The in vitro anti­cancer activity was investigated and DFT calculations were performed to support its anti­cancer activity.

The five-membered ring is slightly ruffled and dihedral angles between the pendant six-membered rings and the central, five-membered ring vary between 50.78 (4) and 86.78 (10)°. In the crystal, O—H⋯N hydrogen bonds and weak π-stacking inter­actions form inversion dimers, which are linked into chains extending along the c-axis direction by two sets of N—H⋯O hydrogen bonds. The chains are connected into layers parallel to the bc plane by two sets of C—H⋯π(ring) inter­actions.

The crystal structure of the title compound consists of ²_∞[Ni₃As₂(OH)_6/3O_18/3O_1/1(OH)_1/1] layers extending parallel to (001) and exhibits disorder of the (O/OH) units of the (hydrogen)arsenate anion; the ammonium counter-cations are sandwiched between adjacent layers.

Two aniline-based tri­fluoro­methyl­sulfonate (tri­fluoro­methane­sulfonate) salts, N,2,4,6-tetra­methyl­anilinium tri­fluoro­methane­sulfonate and N-iso­propyl­idene-N,2,4,6-tetra­methyl­anilinium tri­fluoro­methane­sulfonate, were synthesized and characterized by single-crystal X-ray diffraction.

Very large high-quality crystals of a new member of the family of double nitrates, namely, [La(NO₃)₆]₂[Ni(H₂O)₆]₃·6H₂O, were crystallized in large amounts. The structure was determined via single-crystal X-ray diffraction to high resolution. Extensive structural information, including hydrogen-bonding details, was obtained at the same time.

The title com­pound exhibits the typical rhomboid-like four-membered Sn–OH ring found in all dimeric mol­ecules of monoorganotin(IV)–dihalide–hydroxides, with acute bond angles at the Sn atom, obtuse bond angles at O atoms and shorter Sn—O bond lengths trans to the ethyl groups.

In the crystal, mol­ecules are linked by C—H⋯π inter­actions, forming ribbons along the a axis. Inter­molecular C—H⋯O hydrogen bonds connect these ribbons to each other, forming layers parallel to the (01) plane. The mol­ecular packing is strengthened by van der Waals inter­actions between the layers.

The two independent mol­ecules of C₂₃H₂₁BrN₄O are closely similar and roughly planar except for the isopropyl groups. They are connected by hydrogen bonds of the types N_amide—H⋯N≡C, H_phen­yl⋯O=C and H_phen­yl⋯Br.

The article discusses the phase contrast effect and compare two simulation methods based on different theoretical frameworks. It demonstrates the ability to reproduce the phase effect in experimental data, using a well-known simulation framework McStas.

Reflectivity from liquid surfaces can be accurately obtained from the diffuse scattering signal around the specular reflection measured by grazing incidence off-specular scattering experiments along with the capillary wave model of diffuse scattering. This method allows for a much faster reflectivity profile acquisition and with an improved signal-noise ratio compared to conventional specular reflectometry.

The intrusion of a ternary electrolyte solution (KCl+CaCl₂) in pure silica chabazite is studied. The structural investigations reveal that the composition of the intruded species is different from those of the initial solution and that the K cations are separated from the Ca ones at the beginning of the intrusion. This seems to be due to different mechanisms of desolvation.

iModel is a 3D crystal structure visualization program that allows users to manipulate and customize models. Developed using LabVIEW and Python, it is a potentially powerful tool for crystal structure visualization.

A Python-based software package is presented that can compute the pair angle distribution function from X-ray or electron fluctuation scattering data of disordered materials.

High-p-T [pressure/high-temperature] experiments using monoclinic CrTe₃ as a starting phase result in a novel structural polymorph identified as CrTe₃ (P2/m) using dedicated methods of synchrotron X-ray diffraction and transmission electron microscopy. The magnetic properties of the novel CrTe₃ phase were investigated through temperature- and field-dependent magnetization measurements and correlated with auxiliary theoretical investigations by first-principles electronic structure calculations and Monte Carlo simulations.

Bragg Spot Finder (BSF) is a UNet-based spotfinder with image preprocessing, a UNet segmentation backbone, and post-processing that includes artifact removal and Watershed segmentation. BSF is supported by the Bragg Spot Detection (BSD) benchmark image dataset containing more than 300 images with more than 66 000 spots.

A novel high-efficiency 2D position-sensitive WLSF ZnS:Ag/⁶LiF scintillator detector has been developed at ISIS for single-crystal diffraction applications. More than a factor of 3 improvement in efficiency was achieved with this detector compared with clear-fibre scintillator detectors. Software routines for further optimizations in position sensitivity and uniformity have been implemented for this type of detector. This new high-efficiency double-layer wavelength-shifting-fibre detector concept enables upgrades to the ISIS instrument suite and extends the scientific capabilities of the facility.

The program VUE analyses the distribution of 2D projections in cryoEM and presents this information in a quantitatively exact manner by maps and other diagrams.

This report describes an `order–disorder' transition in the recently discovered K₂Ca₃(CO₃)₄ material and the disordered β modification with an unusual K–Ca isomorphism in cation sites. The appearance of mixed K/Ca sites, in turn, causes strong orientational disorder of anions and the emergence of an inversion center (the ordered α modification is non-centrosymmetric).

First implementation of full-field nano-holotomography in a dual beam configuration.

A collection of personal reminiscences illuminates many widely unknown facts about the first steps of synchrotron radiation research. In particular, the events that brought Frascati close to world leadership in this domain.

A review is presented of the history of ion beam figuring (IBF) and current developments, with a focus on the production of high-quality X-ray optics.

We present the laminography setup and software toolbox for efficient imaging of large-size samples. Applicability of the developed technique is demonstrated with imaging the slabs through the whole mouse brain sample stained with heavy elements.

A novel approach for 6D WAXD tensor tomography characterization based on a concept of virtual reciprocal space scan.

Platinum(II) complexes exhibit intense luminescence based on their molecular arrangement and chromic luminescence, which is a color change in response to gentle stimuli such as vapor exposure or weak mechanical forces. Both the molecular and crystal designs as soft crystals are critical to effectively control the chromic phenomenon of Pt(II) complexes.

Total X-ray scattering measurements of dilute solutions are uniquely well suited to address the structural basis for the effects of solvation, exemplified by the success of small-/wide-angle X-ray scattering studies of macromolecules in solution. Herein, we extend this methodology to the high-energy X-ray regime by developing a theoretical framework to describe the differential solution scattering experiment, supported by numerical simulation and experiment.

The crystal structure of the title complex is stabilized by inter­molecular O—H⋯Cl hydrogen bonds, forming (18) ring motifs.

The cation of the title hydrated salt is a di­aza­borinane featuring substitution at 1, 2, and 3 positions in the nitro­gen–boron six-membered heterocycle. In the crystal, the cations stack along [100] in an alternating head-to-tail manner, while the iodide ion and water mol­ecule form one-dimensional hydrogen-bonded chains beside the cation stack. The cation stacks and I⁻–water chains are crosslinked by N—H⋯I and N—H⋯O hydrogen bonds.

The title compound is a di­aza­borinane featuring substitution at the 1, 2, and 3 positions of the nitro­gen–boron six-membered heterocycle. In the crystal, mol­ecules are stacked in a head-to-tail manner. The iodide ion makes close contacts with three organic mol­ecules and supports the alternating stack.

The mol­ecule of the title NC_NHCS pincer N-heterocyclic carbene palladium(II) complex, [PdBr(C₂₁H₂₅N₃S)]Br, exhibits a slightly distorted square-planar coordination at the palladium(II) atom, with the five-membered chelate ring nearly planar. The six-membered chelate ring adopts an envelope conformation. Upon chelation, the sulfur atom becomes a stereogenic centre with an R_S configuration induced by the chiral carbon of the precursor imidazolium salt.

The π-conjugated planar title mol­ecules are assembled through C—H⋯π inter­actions between neighboring mol­ecules, resulting in stacking along the c-axis.

The title compound crystallizes in space group P2₁/c with four mol­ecules in the asymmetric unit.

The crystal structure model of germacrone type II determined from single-crystal X-ray data is compared with that of a previous synchrotron X-ray powder study

The title compound features bifurcated template-to-framework N—H⋯(O,O) hydrogen bonds.

The title complex exhibits a distorted octa­hedral geometry about the metal centre, which coordinates two tridentate ligands that are perpendicular to each other.

The structure of bis­[2,3-bis­(thio­phen-2-yl)pyrido[3,4-b]pyrazine]­silver(I) perchlorate methanol disolvate is monoclinic. The Ag atom coordinates pyrido N atoms and is two-coordinate; however, the Ag atom has nearby O atoms that can be assumed to be weakly bonding – one from the perchlorate anion and one from the methanol solvate. One of the thienyl groups of a 2,3-bis­(thio­phen-2-yl)pyrido[3,4-b]pyrazine is flipped disordered and was refined to occupancies of 68.4 (6) and 31.6 (6)%.