A new tecton, 1,8-diiodoethynylanthracene, with two halogen-bond donor sites was synthesized and characterized. This tecton is capable of forming two parallel halogen bonds at once, which makes it a useful building block for the construction of a variety of supramolecular squares and rectangles.

An in-depth investigation of the Z′ > 4 structures of organic molecules archived in the Cambridge Structural Database has shown that the group is very diverse but that most structures are the result of a simple modulation and/or of a hydrogen-bonded aggregate that has at most approximate symmetry.

The microstructure of zeolite IM-18 with correlated disorder was elucidated by simulating the diffuse scattering of powder and single-crystal diffraction patterns. The method could be applied to other multidimensional disordered structures.

A structural study of methyl­ammonium lead triiodide [CH₃NH₃PbI₃ (MAPbI₃)], at high pressures up to 20 GPa using noble gases Ne and Ar as pressure-transmitting media is reported. It is found that both noble gases are chemically active at high pressures. In particular, Ne stabilizes the high-pressure structure of Ne_xMAPbI₃ and prevents amorphization up to 20 GPa. In contrast, Ar acts as a stabilizer only up to 2.4 GPa and accelerates irreversible amorphization upon further compression.

We report the experimental observation of a `unique' and `rare' F⋯O interaction, involving two electronegative atoms, having the characteristics of `short interatomic distance' and `high directionality' that provide robustness to the crystal packing. The characterization of these F⋯O contacts via different computational procedures establish the interaction to be dispersive in nature and the mutual polarization of an O atom by F and vice versa provides real physical insights into the role of atomic polarizability in interacting atoms in molecules in crystals.

The high-pressure behaviour of monoclinic phosphoric acid is presented and a new high-pressure orthorhombic phase is reported. The molecule–molecule interaction energies of the orthorhombic phase are shown to be more attractive than those of the low-pressure monoclinic phase.

The structure factors of diamond at 800 K at sin θ/λ ≤ 2.2 Å⁻¹ were determined from multiple overlaid powder profiles. Data correction was essential to extract the Bragg intensities of the weak reflections. The quality of the final charge density determined at 800 K was nearly comparable with that of room-temperature data.

The crystal structure of the mineral meneghinite, CuPb₁₃Sb₇S₂₄, has been solved and refined as an incommensurate structure from X-ray single-crystal diffraction data in four-dimensional superspace. The very small departure from the commensurate value of the modulation raises the question of whether incommensurability in sulfosalts could be much more frequent than previously thought.

A model for the X-ray diffuse scattering from terephthalic acid (C₈H₆O₄) is presented, and used to explore the sensitivity of diffuse scattering to polymorphic interconversion, and to demonstrate the relative ease with which the harmonic (`thermal') component of the diffuse scattering can be modelled.

The combinations of phase transitions which occur in Heusler alloys in terms of order parameters and symmetry have been analysed using a group theoretical approach. It is shown how this approach can be applied to relevant examples.

The complex oxide YCuO_2.66 is shown to be twinned at the nanoscale. Its structure was solved using precession electron diffraction.

Evolutions of microstructure and crystal defects in the nanocrystalline WC–Co composite during room- and high-temperature deformations were studied using molecular dynamics simulations.