issue contents

ISSN: 2052-5206

August 2023 issue

Highlighted illustration

Cover illustration: Through experimental charge density and topological analyses of tetra­aqua­bis­(hydrogenmaleato)nickel(II), Pinto et al. [Acta Cryst. (2023), B79, 282–296] conclude that the nature of Ni—O bonds is intermediate between ionic and covalent, but mainly presenting an ionic character, while the short hydrogen bond can be classified as covalent in nature. Deformation density maps of the hydrogen maleate ligand and three different O—Ni—O planes from multipole model refinement are shown. Arrows indicate the oxygen lone pairs on the hydrogen maleate ligand.


link to html
Introducing the new Section Editor of Acta Crystallographica Section B.

scientific commentaries

link to html
Investigations simultaneously involving multiple techniques of quantum crystallography could be very useful to prove the consistency of obtained results or to highlight different facets of the same scientific phenomenon or problem. Pinto et al. [Acta Cryst. (2023), B79, 282–296] exploit three different quantum crystallographic techniques (Hansen & Coppens multipole model refinement, QTAIM analysis of the electron density, and Hirshfeld atom refinement) to characterize the nature of chemical bonds and of intra/intermolecular interactions in an organometallic compound.

research papers

link to html
The crystal structures of three new MgCo2–xGax (x = 1.0), Mg1–xCo2–yGax+y (x = 0.06, y = 0.64), and Mg1–xCo2–yGax+y (x = 0.10, y = 0.16) phases were determined using X-ray diffraction. These three structures are new ternaryderivatives of the Laves phases.

link to html
The crystal structure of a new FeII-based metal organic framework of composition K2Fe[(C2O4)2(H2O)2]·0.18H2O is resolved using single crystal and powder X-ray diffraction.

link to html
Owyheeite crystallizes as a twofold superstructure. The systematic twinning is due to the rod-polytype character of the structure.

link to html
A comparison between experimental charge density analysis and the Hirshfeld atom refinement procedure for a transition metal coordination compound is given.

link to html
The crystal chemistry of the natural microporous two-layer aluminosilicates latiumite and tuscanite is re-investigated. These 2D zeolites could be considered as prototypes of advanced materials with ion-exchange properties and ion/proton conductivity.

link to html
A series of Bi1–xLaxFeO3 nanocrystalline samples with 0.00 ≤ x ≤ 0.30 was synthesized by the sol–gel method. X-ray diffraction studies revealed composition-driven structural transformation from rhombohedral R3c via cubic Pm3m to orthorhombic Pbam structure, while the analysis of Mössbauer spectra allowed the observation of the gradual deterioration of cyclo­idal spin ordering accompanied by the increase of magnetization.

link to html
The synthesis and crystal structure are reported of a new hybrid perovskite with manganese(II) for which differential scanning calorimetry (DSC) shows two endothermic main peaks at T = 366 K and T = 375 K. These phase transitions have been investigated using powder diffraction which confirms the presence of a major transition around 363 K in relation to the release of the two water molecules coordinated to Mn.

link to html
The superspace approach is used to determine the structure of a modulated form of YZn5+x (x = 0.217), which is an ordered variant of the previously described EuMg5+x-type structure, with its channels containing disordered Zn atoms. The details of the pattern align closely with earlier predictions based on DFT-chemical pressure analysis of ordered models.

link to html
The structure of the pharmaceutical lubricant magnesium stearate has been determined from micrometre-sized single crystals at a fourth-generation synchrotron.

link to html
There is a clear negative correlation between the vanadyl bond lengths and wavenumbers of the bands of V—O stretching vibrations in infrared spectra. For most minerals with vanadyl bonds there is good agreement between measured refractive indices and those calculated based on the polarizability concept.
Follow Acta Cryst. B
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds