Unity gives strength: combining Bertaut's and Belov's concepts and the formalism of aperiodic crystals to solve magnetic structures of unprecedented complexity.

We draw attention to the exceptional work of Geers et al. [(2024). IUCrJ, 11, 910-920] on the analysis of magnetic phases, in which challenging magnetic structures are determined by a combination of modern computational methods and a connection between nuclear modulation and the ordering of magnetic moments is shown.

Observation of a spontaneous anomalous Hall response in the MnSi d-wave altermagnet candidate.

Phases with spontaneous time-reversal ( ) symmetry breaking are sought after for their anomalous physical properties, low-dissipation electronic and spin responses, and information-technology applications. Recently predicted altermagnetic phase features an unconventional and attractive combination of a strong -symmetry breaking in the electronic structure and a zero or only weak-relativistic magnetization. In this work, we experimentally observe the anomalous Hall effect, a prominent representative of the -symmetry breaking responses, in the absence of an external magnetic field in epitaxial thin-film MnSi with a vanishingly small net magnetic moment.

Incommensurate magnetic structure of CrAs at low temperatures and high pressures.

The magnetic structure of chromium arsenide CrAs is studied with neutron powder diffraction at ambient pressure in the temperature range 1.5-300 K as well as with neutron single-crystal diffraction at 2 K and 0.12 GPa.

NiInSb: Synthesis, Crystal Structure, Electronic Structure, and Magnetic Properties.

The ternary phase with the composition NiInSb has been synthesized by high-temperature synthesis and structurally characterized by a combination of X-ray analysis, neutron diffraction analysis, and theoretical calculations. The structure of NiInSb crystallizes in the orthorhombic space group with lattice constants = 7.111(3) Å, = 5.

Dipole-Moment Modulation in New Incommensurate Ferrocene.

Despite 70 years of research on metallocenes and their applications, there are still unresolved regions in its phase diagram of the prototypic sandwich compound, ferrocene Fe[CH] (FeCp), and its molecular 5-fold symmetry cannot be reconciled with the dielectric response of this crystal. We found a new phase I″ of ferrocene, which reveals the relationships between the molecular conformation, intermolecular interactions, and electric permittivity of this compound. Between 172.

Incommensurate structures and radiation damage in RbVO and KVO mixed-valence vanadate fresnoites.

The structures and phase transitions to incommensurate structures in RbVO and KVO mixed-valence vanadate fresnoites are studied with synchrotron single-crystal diffraction at low temperatures and ambient pressure. Although mixed satellite reflections are absent, the modulated structure of KVO below 115 K is better described in (3 + 2)- than in (3 + 1)-dimensional space. The geometries of the VO and VO building units are rigid and it is mainly slight rotations of these polyhedra and small variation of the intermediate K-O distances that are modulated.

Phase Transitions and Physical Properties of the Mixed Valence Iron Phosphate Fe(POOH)(HO).

Iron phosphate materials have attracted a lot of attention due to their potential as cathode materials for lithium-ion rechargeable batteries. It has been shown that lithium insertion or extraction depends on the Fe mixed valence and reduction or oxidation of the Fe ions' valences. In this paper, we report a new synthesis method for the Fe(POOH)(HO) mixed valence iron phosphate.

Metal-free enantiomorphic perovskite [dabcoH][HO]Br and its one-dimensional polar polymorph.

The structure and stoichiometry of a new metal-free and ammonium-free compound [dabcoH]HOBr (where [dabcoH] = 1,4-di-aza-bicyclo-[2.2.2]octane dication) correspond to the general formula characteristic of perovskites.

Hidden and apparent twins in uranyl-oxide minerals agrinierite and rameauite: a demonstration of metric and reticular merohedry.

In this work, the structures of chemically related uranyl-oxide minerals agrinierite and rameauite have been revisited and some corrections to the available structure data are provided. Both structures were found to be twinned. The two minerals are chemically similar, and though their structures differ considerably, their unit-cell metrics are similar.

Crystal structure of the uranyl arsenate mineral hügelite, Pb(UO)O(AsO)(HO), revisited: a correct unit cell, twinning and hydrogen bonding.

Revisiting the structure of uranyl arsenate mineral hügelite provided some corrections to the available structural data. The previous twinning model (by reticular merohedry) in hügelite has been corrected. Twinning of the monoclinic unit cell [a = 7.

Experimental Evidence of the Coexistence of Proper Magnetic and Structural Incommensurability on the [CHNH][Ni(COOH)] Compound.

The present work is dedicated to characterization of the structural phase transition and incommensurate magnetic structure of the [CHNH][Ni(COOH)] () perovskite-like metal-organic compound. The structural and magnetic characterization has been performed through variable-temperature single-crystal and powder neutron diffraction. Compound crystallizes in the orthorhombic space group at room temperature.

Charge density of 4-methyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]thiazole-2(3H)-thione. A comprehensive multipole refinement, maximum entropy method and density functional theory study.

The structure of 4-methyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]thiazole-2(3H)-thione (MTTOTHP) was investigated using X-ray diffraction and computational chemistry methods for determining properties of the nitrogen-oxygen bond, which is the least stable entity upon photochemical excitation. Experimentally measured structure factors have been used to determine and characterize charge density via the multipole model (MM) and the maximum entropy method (MEM). Theoretical investigation of the electron density and the electronic structure has been performed in the finite basis set density functional theory (DFT) framework.

Realization of the kagome spin ice state in a frustrated intermetallic compound.

Spin ices are exotic phases of matter characterized by frustrated spins obeying local "ice rules," in analogy with the electric dipoles in water ice. In two dimensions, one can similarly define ice rules for in-plane Ising-like spins arranged on a kagome lattice. These ice rules require each triangle plaquette to have a single monopole and can lead to different types of orders and excitations.

Structural, mechanical, spectroscopic and thermodynamic characterization of the copper-uranyl tetrahydroxide mineral vandenbrandeite.

The full crystal structure of the copper-uranyl tetrahydroxide mineral (vandenbrandeite), including the positions of the hydrogen atoms, is established by the first time from X-ray diffraction data taken from a natural crystal sample from the Musonoi Mine, Katanga Province, Democratic Republic of Congo. The structure is verified using first-principles solid-state methods. From the optimized structure, the mechanical and dynamical stability of vandenbrandeite is studied and a rich set of mechanical properties are determined.

Supercell refinement: a cautionary tale.

Theoretically, crystals with supercells exist at a unique crossroads where they can be considered as either a large unit cell with closely spaced reflections in reciprocal space or a higher dimensional superspace with a modulation that is commensurate with the supercell. In the latter case, the structure would be defined as an average structure with functions representing a modulation to determine the atomic location in 3D space. Here, a model protein structure and simulated diffraction data were used to investigate the possibility of solving a real incommensurately modulated protein crystal using a supercell approximation.

A commensurately modulated structure of parabutlerite, FeSO(OH)·2HO.

Parabutlerite, orthorhombic FeSO(OH)·2HO, has been reinvestigated using single-crystal X-ray diffraction. The structure of parabutlerite is commensurately modulated, with a = 20.0789 (8), b = 7.

Incommensurately modulated structure of morpholinium tetrafluoroborate and configurational versus chemical entropies at the incommensurate and lock-in phase transitions.

Morpholinium tetrafluoroborate, [CHNO][BF], belongs to a class of ferroelectric compounds ABX. However, [CHNO][BF] does not develop ferroelectric properties because the incommensurate phase below T = 153 K is centrosymmetric with superspace group Pnam(σ00)00s and σ = 0.42193 (12) at T = 130 K; the threefold superstructure below T = 117-118 K possesses the acentric but non-ferroelectric space group P222.

Intricate disorder in defect fluorite/pyrochlore: a concord of chemistry and crystallography.

Intuitively scientists accept that order can emerge from disorder and a significant amount of effort has been devoted over many years to demonstrate this. In metallic alloys and oxides, disorder at the atomic scale is the result of occupation at equivalent atomic positions by different atoms which leads to the material exhibiting a fully random or modulated scattering pattern. This arrangement has a substantial influence on the material's properties, for example ionic conductivity.

Could incommensurability in sulfosalts be more common than thought? The case of meneghinite, CuPbSbS.

The structure of meneghinite (CuPbSbS), from the Bottino mine in the Apuan Alps (Italy), has been solved and refined as an incommensurate structure in four-dimensional superspace. The structure is orthorhombic, superspace group Pnma(0β0)00s, cell parameters a = 24.0549 (3), b = 4.

An exceptional series of phase transitions in hydrophobic amino acids with linear side chains.

The solid-state phase transitions and intermediate structures of -2-amino-butanoic acid (l-2-aminobutyric acid), -2-aminopentanoic acid (l-norvaline), -2-aminohexanoic acid (l-norleucine) and l-methionine between 100 and 470 K, identified by differential scanning calorimetry, have been characterized in a comprehensive single-crystal X-ray diffraction investigation. Unlike other enantiomeric amino acids investigated until now, this group featuring linear side chains displays up to five distinct phases. The multiple transitions between them involve a number of different processes: alteration of the hydrogen-bond pattern, to our knowledge the first example of this observed for an amino acid, sliding of molecular bilayers, seen previously only for racemates and quasiracemates, concerted side-chain rearrangements and abrupt as well as gradual modifications of the side-chain disorder.

New insight on bismuth cuprates with incommensurate modulated structures.

The incommensurate modulated crystal structure of Bi2.27Sr1.73CuO6 + δ (2201) phase [a = 5.

Structure refinement using precession electron diffraction tomography and dynamical diffraction: tests on experimental data.

The recently published method for the structure refinement from three-dimensional precession electron diffraction data using dynamical diffraction theory [Palatinus et al. (2015). Acta Cryst.