Growth and single-crystal refinement of phase-III potassium nitrate, KNO₃

This paper describes a novel method for the room-temperature growth of single crystals of phase-III KNO₃ and refines its structure at both room temperature and 123 K.

Magnetic behaviour of synthetic Co₂SiO₄

The magnetic structure of the synthetic cobalt olivine, Co₂SiO₄, is determined by means of non-polarized and polarized neutron diffraction on single-crystal and powder samples.

Octahedral tilt twinning and compositional modulation in NaLaMgWO₆

Neutron powder diffraction and transmission electron microscopy studies reveal that the ordered perovskite NaLaMgWO₆ has a complex superstructure consisting of a compositional modulation of the A-site cations accompanied by a one-dimensional twinning of the octahedral tilt system.

On the valences of bonds in the oxycomplexes of Sn²⁺

A critique of Wang and Liebau's proposed concept of structural valence is presented.

(111)_p microtwinning in SrRuO₃ thin films on (001)_p LaAlO₃

Extra spots located at one-sixth and one-third positions on 〈110〉_p (p = pseudocubic) zone-axis diffraction patterns were attributed to the existence of high-density twins on {111}_p pseudocubic planes within the SrRuO₃ films rather than to more conventional mechanisms for the generation of superstructure reflections.

Isomorphism in monomeric 1:3 complexes of silver(I) salts with tri-p-tolylphosphine

The synthesis and characterization of isomorphous silver(I) complexes [AgX{P(4-MeC₆H₄)₃}₃] (X = Br, SCN, ClO₄) using single-crystal X-ray diffraction are described and compared with related structures from the literature. The molecular structures of the three complexes are compared using an r.m.s. overlay as well as a half-normal probability plot analysis.

Cluster analyses of metal-organic fragments using the dSNAP software

The dSNAP computer program has been used to classify searches of the Cambridge Structural Database for two ligands commonly found in metal-organic systems.

Experimental and theoretical charge-density study of a tetranuclear cobalt carbonyl complex

Random noise added to theoretical structure factors for a cobalt carbonyl complex is shown to have a large influence on the resulting topological landscape with the potential disappearance of bond-critical points. Atoms in molecules (AIM) analysis of the experimental charge density shows evidence of all the bond-critical points while being highly sensitive to the chosen parameter set.

Molecular and crystalline structures of three (S)-4-alkoxycarbonyl-2-azetidinones containing long alkyl side chains from synchrotron X-ray powder diffraction data

The crystal structures of three (S)-4-alkoxo-2-azetidinecarboxylic acids (with alkoxo = decyloxo, dodecyloxo and hexadecyloxo) were solved and refined from synchrotron X-ray powder diffraction data and compared with density-functional theory calculations.

Comparison of the effects of pressure on three layered hydrates: a partially successful attempt to predict a high-pressure phase transition

Although the monohydrates of betaine, cysteic acid and S-4-sulfo-L-phenylalanine all contain hydrate layers, they differ in the orientations of the water molecules. The topologies of S-4-sulfo-L-phenylalanine and betaine monohydrates led us to predict that the former would undergo a phase transition at high pressure, while the latter would not.

How to easily replace the independent atom model – the example of bergenin, a potential anti-HIV agent of traditional Asian medicine

The detailed electron-density distribution of bergenin, an anti-HIV agent, has been determined. It is shown that even a low-order data set measured at room temperature with Ni-filtered Cu Kα radiation and point detection can provide information far beyond the outcomes of an independent atom model refinement.

Weak intra- and intermolecular interactions in a bi­naphthol imine: an experimental charge-density study on (±)-8′-benzhydryl­idene­amino-1,1′-bi­naphthyl-2-ol

An Atoms in Molecules (AIM) analysis of the experimental and theoretical charge density in the title compound confirms the presence of an intramolecular CH⋯π interaction, which was originally suspected on geometrical grounds. The other weak intra- and intermolecular interactions and π-delocalization effects were examined by AIM topological analysis and ellipticity profiles.

A conformational polymorphic transition in the high-temperature ∊-form of chlorpropamide on cooling: a new ∊′-form

A reversible phase transition into a new polymorph of chlorpropamide on cooling the ∊-form below 200 K has been observed for the first time and followed by single-crystal and powder X-ray diffraction and IR spectroscopy.

Space groups P1 and Cc: how are they doing?

A survey of recent entries in the Cambridge Structural Database suggests that the percentage of structures described in space groups of inappropriately low symmetry has decreased from about 10% in the early 2000s to less than 5% today for space group Cc, but that for space group P1 it remains close to 8%.

Towards a more reliable symmetry determination from powder diffraction: a redetermination of the low-temperature structure of 4-methylpyridine-N-oxide

A low-temperature structure of the title compound was redetermined in the correct space group. The symmetry was determined ab initio by a recently published symmetry-determination algorithm.

[Ru(py)₄Cl(NO)](PF₆)₂·0.5H₂O: a model system for structural determination and ab initio calculations of photo-induced linkage NO isomers. Erratum

Erratum to Cormary et al. (2009), Acta Cryst. B65, 612–623.

Clara Brink Shoemaker (1921–2009)