The following articles are a selection of those recently accepted for publication in Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials.
(Na,□)5[MnO2]13 nanorods: a new tunnel structure for electrode materials determined ab-initio and refined through a combination of electron and synchrotron diffraction data
Octahedral molecular sieves (OMS) attract increasing interest in the search for novel electrode materials for energy storage and water desalination. While a nanometric particle size is desirable for such applications, this makes ordinary single-crystal characterization difficult and many OMS structures are still waiting for elucidation. Here, we present the long awaited structure of a well known material, (Na,□)5[MnO2]13, resolved by a combination of electron diffraction tomography, dynamical scattering theory and X-ray powder Rietveld refinement. A new type of tunnel structure was found, able to explain previously reported electrochemical properties. This structure also suggests a possible mechanism for topotactic transformations between different manganese oxide OMS frameworks.
Hydrogen-substituted β-tricalcium phosphate synthesized in organic media
A hydrogen substitution mechanism, previously unknown in pure β-tricalcium phosphate, was discovered in crystals precipitated from ethylene glycol solutions. The structure was described by means of Rietveld refinement of powder X-ray diffraction data and corroborated by chemical analysis and IR spectroscopy.
Accurate and efficient representation of intramolecular energy in ab initio generation of crystal structures. I. Adaptive local approximate models
This article describes an important improvement in the CrystalPredictor II code: adaptive Local Approximate Models (LAMs). This improvement allows the most efficient use of computational effort to cover a flexible molecule's conformational space, and is illustrated with a crystal structure prediction (CSP) investigation into the sixth blind test molecule 26.
Two cubic phases in kimzeyite garnet from the type locality Magnet Cove, Arkansas
Two cubic phases in a kimzeyite crystal create optical anisotropy that results from strain originating from structural mismatch. Two different mechanisms, namely epitaxial growth and exsolution on cooling, give rise to the two phases.
CuII and ZnII β-diketonate coordination polymers based on pyrimidin-2-amine, pyrazine and 1,2-bis(4-pyridyl)ethane
The supramolecular potential of pyrimidin-2-amine has been evaluated in comparison with the well established bridging ligands pyrazine and 1,2-bis(4-pyridyl)ethane on the 4,4,4-trifluoro-1-phenylbutane-1,3-dionato copper(II) and zinc(II) moieties.
Solvates of selected fenamic acids with substituted pyridines: structure, thermal stability and desolvation
Mefenamic acid and tolfenamic acid form solvates with selected substituted pyridines. The crystal structures, thermal stability, desolvation studies and other modes of preparation were also determined.
Vacancy pairing and superstructure in the high-pressure silicate K1.5Mg2Si2O7H0.5: a new potential host for potassium in the deep Earth
The superstructure of a novel high-pressure hydrous silicate K1.5Mg2Si2O7H0.5 relevant to the water budget of the Earth's mantle has been determined and its crystal chemistry discussed in relation to its stabilization at mantle conditions.
Neutron and high-pressure X-ray diffraction study of hydrogen-bonded ferroelectric rubidium hydrogen sulfate
The hydrogen-bonded ferroelectric material rubidium hydrogen sulfate has been investigated through a combination of high-pressure X-ray diffraction and neutron Laue diffraction. This study confirms the order–disorder origin of the ferroelectric transition as well as fully characterizing the high-pressure phase transition.