The structural science of functional materials

The growing complexity of functional materials and the major challenges this poses to structural science are discussed. The diversity of structural materials science and the contributions that computation is making to the field are highlighted.

Carbonic anhydrase under pressure

Investigations of the rapid enzyme carbonic anhydrase have now been extended by crystallographic analysis at high CO₂ pressures to examine the movements of water molecules in different steps of the catalysis. The rate of catalysis seems well explained by the assembled observations.

Hydrogen bonds in crystalline D-alanine: diffraction and spectroscopic evidence for differences between enantiomers

Neutron powder diffraction from D-alanine, a D-form amino acid present in higher animals including humans, shows subtle structural differences when compared with its enantiomer, L-alanine. These dissimilarities are due to different rearrangements of the NH₃⁺ group as revealed by Raman scattering.

Building inorganic supramolecular architectures using principles adopted from the organic solid state

The possibility of converting crystal engineering principles that originate in the organic solid state into productive strategies for the effective supramolecular assembly of coordination complexes has been established through a range of complementary techniques. Calculated molecular electrostatic potentials, in conjunction with a systematic structural study, demonstrate that the existence and structural importance of the key hydrogen-bond interactions are not disrupted by the presence of metal cations and charge-balancing anions.

An unprecedented dioxygen species revealed by serial femtosecond rotation crystallography in copper nitrite reductase

The observation of O₂ in a time-frozen structure using serial femtosecond rotation crystallography of the as-isolated oxidized enzyme provides long-awaited clear-cut evidence for the mode of O₂ binding in CuNiRs. This provides an insight into how CuNiR from A. xylosoxidans can function as an oxidase, reducing O₂ to H₂O₂, or as a superoxide dismutase (SOD) since it was shown to have ∼56% of the dismutase activity of the bovine SOD enzyme some two decades ago.

Probing the accuracy and precision of Hirshfeld atom refinement with HARt interfaced with Olex2

Anisotropic atomic displacement parameters obtained separately from highly accurate X-ray and neutron diffraction data are compared, and it is established that Hirshfeld atom refinement of X-ray data can provide structural parameters that are as accurate as those from neutron data.

Snapshot and crystallographic observations of kinetic and thermodynamic products for NO₂S₂ macrocyclic complexes

The complexation of an NO₂S₂ macrocycle with CdI₂ offers an opportunity to identify the kinetic and thermodynamic products via visual methods because the direct observation and structural characterization of each product were available from sequential snapshots, single-crystal X-ray structures and powder X-ray diffraction patterns.

Phase transition and magnetocaloric properties of Mn₅₀Ni_42−xCo_xSn₈ (0 ≤ x ≤ 10) melt-spun ribbons

Mn₅₀Ni_42−xCo_xSn₈ melt-spun ribbons exhibit strong magnetostructural coupling over a wide temperature range from 222 to 355 K. The ΔS_M^peak and RC_eff in Mn₅₀Ni_42−xCo_xSn₈ melt-spun ribbons are comparable with or even superior to those of Ni-rich Ni–Mn-based polycrystalline bulk alloys.

Determination of atomic vacancies in InAs/GaSb strained-layer superlattices by atomic strain

Atomic vacancies in complex crystals can be determined by atomic-resolution strain mapping at picometre precision using scanning transmission electron microscopy. The method is applied to InAs/GaSb superlattices.

Local-scale structures across the morphotropic phase boundary in PbZr_1−xTi_xO₃

Using neutron total scattering and pair distribution function analysis, this work discusses how the complex local structure in lead zirconate titanate affects the long-range average structure across the morphotropic phase boundary, and its influence on the unique piezoelectric properties.

Crystal structure of peroxiredoxin 3 from Vibrio vulnificus and its implications for scavenging peroxides and nitric oxide

The crystal structure of a bacterial 1-Cys peroxiredoxin has been solved, revealing an oligomeric interface.

Active-site solvent replenishment observed during human carbonic anhydrase II catalysis

Ultrahigh-resolution crystallographic structures of human carbonic anhydrase II (hCA II) cryocooled under CO₂ pressures of 7.0 and 2.5 atm are presented. The structures reveal new intermediate solvent states of hCA II that provide crystallographic snapshots during restoration of the proton-transfer water network in the active site.

Resolution extension by image summing in serial femtosecond crystallography of two-dimensional membrane-protein crystals

The resolution limit of serial diffraction from two-dimensional crystals at a free-electron laser was extended to the detector edge (4 Å) by exploiting the large redundancy of the data set.