forthcoming articles
The following articles are a selection of those recently accepted for publication in IUCr journals.



Crystal engineering of ionic cocrystals comprising Na/K salts of hesperetin with hesperetin molecules and solubility modulation
Synthesis and property evaluation of ionic cocrystals and salts of the weakly acidic nutraceutical compound hesperetin support the reliability of crystal engineering approaches based on the PhOH⋯PhO− supramolecular heterosynthon and the effectiveness of cocrystallization in tackling low aqueous solubility for a weakly ionisable compound.

Hierarchical packing of racemic metallosupramolecular cages with Ni(II)-based triple-stranded helicate building blocks
Racemic metallosupramolecular cages were fabricated from homochiral Ni(II)-based triple-stranded helicate building blocks. In hierarchical crystal packing, methyl groups of a cage can be accommodated in cone-shaped metal cluster metallocavitands of adjacent cages in the form of host–guest interactions.

Classification of perovskite structural types with dynamical octahedral tilting
Here, a new class of dynamically distorted perovskite structures is proposed. Based on a complete table of all possible structures, experimental data are re-examined and space group relationships are explained. A list of characteristic features of dynamically distorted perovskite structures is also provided.
![]() | Acta Crystallographica Section A Acta Crystallographica Section A FOUNDATIONS AND ADVANCES |

On the combinatorics of crystal structures. II. Number of Wyckoff sequences of a given subdivision complexity
Both a generating polynomial and dynamical programming method, respectively, to calculate the number of distinct Wyckoff letter sequences of a chosen space-group symmetry (obligatory) and length (optionally) are presented, taking into account specified values for the combinatorial and coordinational degrees of freedom, thereby representing crystal structures of invariant subdivision complexity.

Crystal search – feasibility study of a real-time deep learning process for crystallization well images
Four deep learning architectures were applied and SqueezeNet scored best. It was combined with the grid programming system BOINC to realize automatic real-time scoring of crystallization well images. Scores are written to a database and displayed to facilitate image inspection for users.



Revisited relativistic Dirac–Hartree–Fock X-ray scattering factors. II. Chemically relevant cations and selected monovalent anions for atoms with Z = 2–112
Fully relativistic X-ray scattering factors for 305 chemically relevant cations, six monovalent anions (O−, F−, Cl−, Br−, I−, At−), the excited (valence) ns1np3 states of carbon and silicon, and five exotic cations for atoms with Z > 104 (Db5+, Sg6+, Bh7+, Hs8+ and Cn2+) have been determined in the 0 ≤ sin θ/λ ≤ 6 Å−1 range using one-electron wavefunctions evaluated via the B-spline Dirac–Hartree–Fock method of Zatsarinny & Froese Fischer [Comput. Phys. Comm. (2016), 202, 287–303]. The study also reports the analytical conventional and extended interpolating functions for the 0–2 and 2–6 Å−1 sin θ/λ intervals and includes a thorough comparison with results from the earlier investigations.
![]() | Acta Crystallographica Section B Acta Crystallographica Section B STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS |

A topological approach to reconstructive solid-state transformations and its application for generation of new carbon allotropes
A novel approach is proposed for the description of possible reconstructive solid-state transformations, which is based on the analysis of topological properties of atomic periodic nets and relations between their subnets and supernets. This approach is applied to generate 72 new carbon allotropes from the initial experimentally proved crystalline carbon structures and found four allotropes, whose hardness is close to diamond.
![]() | Acta Crystallographica Section C Acta Crystallographica Section C STRUCTURAL CHEMISTRY |

Double-salt formation in crystal structures containing [Co(en)3]Cl3
The structures of the isostructural sodium, potassium, and ammonium double salts of [Co(en)3]Cl3 (en is ethane-1,2-diamine) have been determined and, compared with the parent compound, show a modest increase in the unit-cell volume.

Structure determination of a bis[4-(di-n-butylamino)phenyl](pyridin-3-yl)borane tetramer highlighting a unique geometric conformation of the core 16-membered ring
The tetramer of bis[4-(di-n-butylamino)phenyl](pyridin-3-yl)borane was synthesized unexpectedly and crystallized. Its structure contains an unusual 16-membered ring core made up of four (pyridin-3-yl)borane groups. The ring adopts a conformation with pseudo-S4 symmetry that is very different from the two other reported examples of this ring system.
![]() | Acta Crystallographica Section D Acta Crystallographica Section D STRUCTURAL BIOLOGY |


Structure of reverse gyrase with a minimal latch that supports ATP-dependent positive supercoiling without specific interactions with the topoisomerase domain
The latch domain in reverse gyrases mediates the cooperation of helicase and topoisomerase domains. In T. maritima reverse gyrase this latch can be designed into a minimal β-bulge loop that has natural precedence in T. africanus reverse gyrase. The properties and functionalities of different latch domains across reverse gyrases are discussed.

Statistical analyses of the oxidized P-clusters in MoFe proteins with the bond-valence method: towards their electron transfer in nitrogenases
The bond-valence method with weighting schemes statistically concludes that the reduction of P-clusters to PN clusters by two electrons correspond to a double protonation with decoordination of the serine residues and the peptide chain of cysteine in MoFe proteins.


Conformational transition of the Ixodes ricinus salivary serpin Iripin-4
The crystal structures of two important conformations of a new serpin from I. ricinus, namely the partially stressed native and cleaved conformations, were solved at 2.3 and 2.0 Å resolution, respectively. The importance of the reactive-centre loop in protease inhibition was also confirmed.

The structure of the complex between the arsenite oxidase from Pseudorhizobium banfieldiae sp. strain NT-26 and its native electron acceptor cytochrome c552
The crystal structure of the electron-transfer complex between arsenite oxidase (AioAB) from Pseudorhizobium banfieldiae sp. strain NT-26 and its native electron acceptor cytochrome c552 (cytc552) is presented. Cytc552 docks within a cleft at the interface of the AioA and AioB subunits, which allows a close association between redox cofactors.; this close association presumably facilitates fast electron transfer and underpins the ability of this organism to respire in arsenic-contaminated environments.

Structures of L-proline trans-hydroxylase reveal the catalytic specificity and provide deeper insight into AKG-dependent hydroxylation
L-Proline trans-hydroxylase and its complexes with substrate and product reveal the structural basis of trans–cis proline hydroxylation selectivity. Structure-based sequence alignment and structural comparison suggest signatures for in-line or off-line AKG-binding modes in AKG-dependent hydroxylases and provide deeper insight into AKG-dependent hydroxylation.

Multivariate estimation of substructure amplitudes for a single-wavelength anomalous diffraction experiment
A new equation for the calculation of substructure-factor amplitudes for substructure detection from a single-wavelength anomalous diffraction experiment produces better results compared with the currently used estimates in test cases.


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![]() | Acta Crystallographica Section E Acta Crystallographica Section E CRYSTALLOGRAPHIC COMMUNICATIONS |

Synthesis, crystal structure and Hirshfeld surface analysis of the hybrid salt bis(2-methylimidazo[1,5-a]pyridin-2-ium) tetrachloridomanganate(II)
The 0-D hybrid salt (C8H9N2)2[MnCl4] with a pseudo-layered arrangement of the organic and inorganic sheets is isomorphous with the Zn and Cd analogues. According to the Hirshfeld surface analysis, non-conventional C—H⋯Cl—Mn hydrogen bonding is predominant in the crystal packing.

Crystal structures of (12E)-12-(4-benzylidene)-7,7,16-trimethyl-3-(4-methylphenyl)-1-oxa-16-azatetracyclo[11.2.1.02,11.04,9]hexadeca-2(11),4(9)-dien-5-one and (12E)-12-(4-bromobenzylidene)-73-(4-bromophenyl)-,7,16-trimethyl-10-oxa-16-azatetracyclo[11.2.1.02,11.04,9]hexadeca-2(11),4(9)-dien-5-one
The title compounds, C32H35NO2, (I), and C30H29Br2NO2, (II), differ by the presence of a bromine atom instead of a methyl atom in the para position of two phenyl rings of compound (II), with an r.m.s. deviation of 0.27 Å between these compounds.


A mixed phosphine sulfide/selenide structure as an instructional example for how to evaluate the quality of a model
A sulfide/selenide solid-solution crystal structure is presented with an emphasis on model building and refinement. Some strategies and statistics for how to assess the accuracy of alternate models are described, including pitfalls, in the context of an instructional example that could be used as an activity in a classroom setting.
![]() | Acta Crystallographica Section F Acta Crystallographica Section F STRUCTURAL BIOLOGY COMMUNICATIONS |


Monomeric crystal structure of the vaccine carrier protein CRM197 and implications for vaccine development
The first crystal structure of the widely used vaccine carrier protein CRM197 in its monomeric form reveals features underlying its dimerization and vaccine-conjugation reaction.

A partially open conformation of an androgen receptor ligand-binding domain with drug-resistance mutations
A partially open conformation of the human androgen receptor ligand-binding domain containing four drug-resistance mutations, L702H/H875Y/F877L/T878A, was observed. Of these mutations, both L702H and F877L are important for this conformation, which may affect ligand binding as well as resistance to antagonists.

![]() | Journal of Applied Crystallography Journal of Applied Crystallography |

101 contact twins in gypsum experimentally obtained from calcium carbonate enriched solutions: mineralogical implications for natural gypsum deposits
Identifying the impurities able to promote the selection of specific gypsum twin laws has relevant implications for the geological studies aimed at interpreting the gypsum depositional environments in ancient and modern deposits. The results of this study provide new insights into the mineralogical implications of twinned gypsum crystals and should help future research to make a better use of the twin laws observed in gypsum in ancient sedimentary successions as a proxy for the chemistry of the original brine.

SpatDistCalib: a GUI Python software for spatial-distortion correction of 2D detectors using splines
In this article, Python software with a graphical user interface for spatial-distortion correction, using any regular grid as the calibration pattern, producing spline files, is presented.

Inserexs: reflection choice software for resonant elastic X-ray scattering
Inserexs is an open-source program that allows resonant elastic X-ray scattering users to choose the best conditions to determine any parameter of interest (atomic position, occupancy etc.) before an experiment is carried out.

Anisotropy factors in small-angle scattering for dilute rigid-rod suspensions
In small-angle scattering, the orientation of long thin particles often results in anisotropic two-dimensional scattering patterns, for which the anisotropy can be quantified through simple anisotropy factors. This work provides practitioners with information on the various methods for determining the anisotropy, including their limitations and recommended applications.

X-ray powder diffraction in education. Part II. Intensity of a powder pattern
The most commonly used functions for calculating or correcting step-scan and integrated intensities of a powder diffraction pattern are presented in an educational manner with the support of Mathematica scripts. The scripts can be easily used by interested readers to explore the effects of different instrumental and sample parameters.

Controlling the magnetic structure in W-type hexaferrites
Abstract Using neutron powder diffraction on W-type hexaferrites, planar magnetic ordering described in Cm'cm' was found for SrCo2Fe16O27 and SrCoZnFe16O27, while SrZn2Fe16O27 had uniaxial ordering described in P63/mm'c'. Thermomagnetic measurements above room temperature also indicated magnetic transitions for SrCo2Fe16O27 and SrCoZnFe16O27.

Local variations of the piezoelectric properties of a LiNb(1−x)TaxO3 crystal
Because of the big difference in the piezoelectric moduli between lithium niobate and lithium tantalate, variation of the piezoelectric properties in local regions of the crystal can appear. A correlation between the change in the piezoelectric properties and the composition in a mixed lithium niobate–tantalate crystal was established.

Pair distribution function analysis of nano-object assemblies
This work extends the application of atomic pair distribution function (PDF) techniques to systems of nanoparticle-based materials. The nano-DPF analysis method provides an effective route to revealing not only nanoscale but also mesoscale structural properties, such as the morphology of a nano-assembly. The approach is of relevance to research fields such as nano-object (e.g. colloids, micelles, proteins) based materials and small-angle scattering.

An inclined detector geometry for improved X-ray total scattering measurements
An inclined geometry is investigated for X-ray total scattering measurements using a digital flat-panel area detector. The inclined geometry enables acquisition of higher quality data for simultaneous Rietveld refinement and total scattering studies, yielding structural information in the short-, medium- and long-range orders from one single measurement.

Energy-dispersive X-ray stress analysis under geometric constraints: exploiting the material's inherent anisotropy
The single-crystal elastic anisotropy and the anisotropy of the near-surface (residual) stress state of polycrystalline materials with random texture are exploited in energy-dispersive X-ray stress analysis to study samples under constrained measurement conditions.
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![]() | Journal of Synchrotron Radiation Journal of Synchrotron Radiation |

A new full-field XRF imaging station at Synchrotron Light Research Institute
This paper describes development of a full-field XRF imaging technique using a large synchrotron X-ray beam at Synchrotron Light Research Institute (Nakhon Ratchasima, Thailand). Various tests were conducted to determine experimental specifications and performance. The experimental results include spatial resolution, 68 µm; Zn detection limit, 0.03%wt. and Zn Kα peak-to-background ratio, 520:1. Elemental distribution images were reported for dendritic limestone, corroded bronze and dried fish, respectively.


MRT-Boost as the last fraction may be the most efficient irradiation schedule for increased survival times in a rat glioma model
We demonstrate in a 3 × 11 Gy radiation treatment that the MRT boost has to be delivered as the last fraction to be more efficient for brain tumor control.

A new satellite of manganese revealed by extended-range high-energy-resolution fluorescence detection
We have discovered a new physical process in manganese, present for manganese-containing materials and materials science, by applying our new technique XR-HERFD, developed from high resolution RIXS and HERFD.


High-energy synchrotron-radiation-based X-ray micro-tomography enables non-destructive and micro-scale palaeohistological assessment of macro-scale fossil dinosaur bones
Synchrotron-radiation-based X-ray micro-tomography at beamline BL28B2 at SPring-8 (Hyogo, Japan) enables the non-destructive assessment of palaeohistological features in dense, fossilized bones of an allosauroid dinosaur, Fukuiraptor kitadaniensis, demonstrating its effectiveness in virtual palaeohistology.



Catalytic reactor for operando spatially resolved structure–activity profiling using high-energy X-ray diffraction
This study introduces a catalytic profile reactor capable of simultaneously measuring spatially resolved temperature, concentration and X-ray diffraction profiles through a catalytic fixed bed under operation. The profile reactor is a versatile and accessible research tool, allowing the usage of multiple synchrotron-based characterization methods to understand and systematically optimize a wide range of catalytic systems.
![]() | IUCrData IUCrData |

5-([(Z)-Methoxyimino]{2-[(2-methylphenoxy)methyl]phenyl}methyl)-1,3,4-oxadiazole-2(3H)-thione dimethyl sulfoxide monosolvate
The title compound crystallizes in the monoclinic space group P21/c with one molecule in the asymmetric unit. In the crystal,
(9) chains of C—H⋯O interactions are formed, propogating in the c-axis direction. The N—H hydrogen atom forms a strong hydrogen bond with the oxygen atom of a DMSO solvate molecule.