Evaluating the relationship between crystal structures of V and hydrogen diffusion to extract key features is important for understanding the relationship between hydrogen diffusion behavior and crystal structure in metals. We applied an image fusion method to surface image datasets of the vanadium alloy (a single-phase bcc V-10 mol% Fe alloy) sample, obtained through different measurement methods, such as optical microscopy, scanning electron microscopy/energy-dispersive X-rays, and electron backscatter diffraction, to construct a multimodal dataset comprising hydrogen distribution and crystallographic orientation image data. The analysis of fused multimodal data by two unsupervised learning methods, such as principal component analysis and multivariate curve resolution, revealed that the hydrogen diffusion behavior differed depending on the crystallographic orientation. For example, grains oriented along the [111] and [101] directions exhibit greater hydrogen diffusion behavior than those oriented along the [001] direction. This trend was consistently observed across various analysis methods, but not when analyzed individually. In addition, it was also suggested that the shift from a pure orientation or the presence of other orientations changes the hydrogen diffusion behavior. Through multimodal data analysis of vanadium alloys, key characteristics of crystal orientation that affect hydrogen diffusion rate were extracted.
The crystallographic orientation of magnesium deposition is closely related to interfacial interactions between the substrate and deposited metal, which critically influences the morphology evolution and reversibility of magnesium metal anodes. Herein, vertically aligned nickel phosphide nanoarrays grown on nickel foam (Ni2P@NF) are constructed to regulate the nucleation and growth behavior of magnesium at the electrode-electrolyte interface. Density functional theory calculations reveal that the Mg (002)/Ni2P interface possesses the lowest interfacial formation energy and favorable adsorption characteristics, enabling preferential Mg nucleation along the thermodynamically favorable Mg (002) plane. The low lattice mismatch between Mg and Ni2P further promotes the epitaxial growth of Mg (002), achieving a smooth and dense magnesium deposition layer. Experimental observations confirm that magnesium deposition on Ni2P@NF exhibits highly uniform morphology and significantly improved reversibility compared with pristine NF. The Ni2P@NF electrode delivers a reduced nucleation overpotential and stable magnesium plating/stripping behavior for over 1260 h at 1 mA cm-2. Furthermore, full cells paired with a Mo6S8 cathode exhibit enhanced rate capability and long-term cycling stability. This work provides new insights into crystallographic regulation of metal deposition at heterogeneous interfaces and offers an effective strategy for stabilizing magnesium metal anodes.
Chemical oxidation of coronene with [Et3O+SbCl6 -] in dichloromethane allowed the isolation and crystallization of a dimeric coronene radical cation in the form of [(C24H12)2 •+(SbCl6 -)]-[Et3O+SbCl6 -]2, as revealed crystallographically. The crystal structure exhibits π-stacked columns of coronene molecules, wherein alternating average interplanar contacts of 3.357(2) and 3.452(2) Å show the distinct formation of the coronene dimers. This packing is accompanied by an atom-over-atom overlap motif and core deformation often associated with a unique intermolecular interaction called pancake bonding. A combined computational analysis employing finite cluster and periodic density functional theory (DFT) calculations confirms the presence of pancake bonding and delineates its hierarchical strength along the column. Charge-distribution analyses identify the molecular oxidation states and demonstrate that Coulombic repulsion between charged dimers plays a decisive role in enforcing the observed alternation of interplanar distances. Periodic DFT modeling of an infinite coronene stack faithfully reproduces the experimental structural parameters and provides insight into the electronic structure of the resulting one-dimensional π-radical assembly.
Misfolded proteins, if not refolded by molecular chaperones, are typically targeted for degradation by cellular quality control systems or tend to aggregate. In the present study, we report a rarely observed crystal structure of a misfolded structure that exists as a stable monomer in solution. The CT375 protein from Chlamydia trachomatis, annotated as a putative d-amino acid dehydrogenase (DAADH), was confirmed to contain the flavin adenine dinucleotide (FAD) through ultraviolet-visible absorption spectroscopy and liquid chromatography-mass spectrometry analyses. However, high-resolution electron density maps excluded the presence of an FAD cofactor bound within the crystallized CT375. This abnormal apo conformation cannot be explained by the loss of FAD during crystallization, as the loop aberrantly occupying the active pocket cannot transition between its current conformation and the FAD-bound conformation observed in homologous oxidoreductases without passing through a two-stranded β-sheet. It is likely that the interactions between this misfolded loop, instead of FAD, and the active pocket residues contribute to stabilizing the overall fold of CT375 in this misfolded state, and that the misfolded protein, present within the heterogeneous CT375 sample, was fortuitously crystallized. The structure of misfolded CT375 underscores the critical role of the cofactor in correct protein folding and provides a valuable model for advancing the understanding of protein misfolding and its potential mechanisms underlying protein dysfunction.
Crystalline materials that undergo coupled structural and optical transformations in response to external stimuli are of broad interest in solid-state chemistry. Here, we report a crystalline hybrid copper phosphate, Cu4(4,4'-bipy)4(H2PO4)4·6H2O, that exhibits solvent-programmable structural and optical switching driven by dehydration and methanol uptake. The material crystallizes with undercoordinated Cu(i) centers in a porous framework stabilized by π-π stacking and hydrogen bonding. Upon heating, dehydration induces a reversible color change from yellow to deep red, accompanied by a crystallographic transformation from a low-symmetry triclinic phase to a higher-symmetry monoclinic phase with distorted tetrahedral Cu coordination. Variable temperature X-ray diffraction and UV-vis spectroscopy correlate this transformation with a red-shift in the metal-to-ligand charge transfer (MLCT) band. Exposing the dehydrated phase to dry methanol drives a different symmetry-breaking crystallographic transformation, in which ordered, directional methanol-framework interactions stabilize trigonal planar Cu(i) centers and produce a distinct cyan color. Together, these results demonstrate how solvent identity, hydrogen bonding directionality, and coordination geometry can be crystallographically coupled to achieve multiple optical responses and switching in a single hybrid phosphate material. This work establishes hybrid phosphate frameworks as a platform for post-synthetic structural and optical switching, accessing crystalline phases that are unreachable through traditional synthetic routes.
The inclusion of the metal based therapeutic ions into bioactive glasses received potential towards tissue regeneration applications due to their excellent biocompatible, mechanical and wear properties. In the current work, one such configuration is chosen, strontium (Sr) and Copper (Cu) ions based bioactive borosilicate glass system i.e., [Formula: see text] with varying composition of Sr and Cu for 0, 1 and 2 wt.%. The glasses were prepared through melt quench process and the as prepared specimens are characterized for their microstructural, mechanical, tribological, biocompatible and biological investigations. The results were found to appealing with microstructure and crystallographic peaks displaying the presence of extracted natural Silica (Si) and Calcium (Ca) powders. Further the same specimens are characterized for their mechanical strength and it was found to be 55.21MPa compressive strength and lowest specific wear rate overall for CuSr-1 wt.% composition. Being CuSr-1% displaying better mechanical properties, the same samples i.e., Cu, Sr for 1wt.%, were investigated for their biocompatible studies through Simulated Body Fluid immersion protocol. The SBF studies indicate the formation of hydroxyapatite that can be inferred from crystallographic peaks and Fourier Transform Infrared Spectroscopy. The samples were also exposed to antibacterial studies against Escherichia coli (E. coli) and Staphylococcus aureus (S.aureus) and are found to exhibit excellent antibacterial activity. The observed selective antibacterial activity highlights the potential of these bioactive glasses as advanced materials for load-bearing orthopaedic implants and bone tissue engineering scaffolds, where the simultaneous requirements of mechanical robustness and antimicrobial efficacy are critical for clinical success.
Enamel covers teeth, is the hardest tissue in the vertebrate body and has a complex multiscale structure from nanometres to millimetres1. The structure comprises thin, long hydroxyapatite (Ca5(PO4)3OH) nanocrystals2, 50-70 nm wide, many micrometres long, parallel and bundled into approximately 5-µm-wide rods. The rods undulate and cross into a microscale 'decussation pattern' that toughens enamel by deflecting cracks3,4. However, the crystallographic orientation of enamel nanocrystals is poorly understood. Here we show that the misorientation angle of adjacent nanocrystals varies markedly across 12 primate teeth spanning 9 species, 17.8 million years of evolution and diverse diets. Using a method called Polarization Enabled Large Input of Crystal Angles at the Nanoscale (PELICAN)5, we compare nanocrystals in the same (pre)molar locations and show that misorientation increases with food hardness in extant and fossil non-human apes and monkeys. We compare misorientation across three major dietary shifts in human evolution: the transition to meat-eating about 2.0-1.5 million years before present6,7, to agriculture (about 12,000 years before present)8,9, and the Industrial Revolution (about 250 years before present)10. We show that over the past 1.6 million years, in the human lineage misorientation increased with time, especially when meat and stone-ground grains were introduced into human diets, but not with the Industrial Revolution. Thus, besides macro-changes, teeth adapted to dietary change at the nanoscale and crystallographically. This observation suggests that misorientation may contribute to enamel's resilience; thus, bioinspired materials may consider small misorientation angles for added resilience.
Metastable allotropes of silicon recovered from high-pressure conditions exhibit a wide range of crystal structures, physical properties and transformation pathways that remain only partially understood despite decades of study. This article combines original crystallographic observations with a critical review of phase transformations, nucleation mechanisms and crystal growth processes in elemental Si and Na-Si systems synthesized under high-pressure, high-temperature conditions. Using in situ diffraction data, structural characterization and computational approaches, we analyze how symmetry breaking, lattice instabilities and kinetic constraints govern the formation of dense polymorphs (Si-II, Si-III, Si-XI) and open-framework structures, including clathrate and channel phases. Particular attention is given to the role of large-volume synthesis and chemically assisted growth routes in controlling phase selection, defect formation and recoverability. The evolution of hexagonal polytypes, including nanostructured 6H silicon, is discussed in terms of stacking modifications driven by stress release and thermal treatment. By integrating crystallographic relations, thermodynamic considerations and growth kinetics, this work identifies phase-transformation mechanisms as the key factor linking structure, synthesis conditions and functional properties of silicon allotropes. The results provide a unified framework for understanding crystal growth at high pressure and offer guidance for the controlled synthesis of advanced silicon materials.
Four-coordinate transition metal complexes with unpaired electrons (S ≥ 1) typically exhibit structures deviated from perfect Td geometry, leading to magnetic anisotropy. (NEt4)2[CoX4] (X = Cl, Co-Cl; Br, Co-Br; I, Co-I) with pseudotetrahedral structures are an ideal series to explore how deviation from perfect Td geometry is reflected in magnetic anisotropy. This work presents comprehensive studies of Co-X, including single-crystal X-ray diffraction of Co-Cl and Co-I, measurements of DC and AC magnetic susceptibilities, inelastic neutron scattering (INS), far-infrared magneto-spectroscopy (FIRMS), and high-frequency and -field electron paramagnetic resonance (HFEPR). Both [CoCl4]2- and [CoBr4]2- ions have crystallographically imposed D2d symmetry, while the [CoI4]2- ion adopts slightly distorted tetrahedral geometry approximating D2d symmetry. Magnetic anisotropy increases from Co-Cl to Co-I. Also, only Co-Cl and Co-Br show field-induced SMM behaviors. FIRMS of Co-I reveals spin-phonon couplings, suggesting that these couplings may lead to fast magnetic relaxation and the lack of SMM behavior. Ligand field theory calculations indicate that an increase in spin-orbit couplings (SOC) from Co-Cl to Co-Br and to Co-I leads to increased magnetic anisotropy. These compounds provide insight into how crystal fields, crystallographic symmetries, and SOC affect magnetic anisotropy and spin relaxation in a well-defined series of homoleptic complexes.
Ultra-narrowband materials provide exceptional spectral purity for high-resolution imaging, precision sensing, and advanced photonic applications, yet molecular systems achieving ultra-narrowband absorption in the short-wave infrared (SWIR) remain exceedingly rare. This scarcity arises from the intrinsic trade-off between long-wavelength absorption, vibrational broadening, and the structural disorder that typically emerges during disordered aggregation. Here, we introduce SWIR cyanine dyes rationally engineered through controlled steric hindrance, sulfonate-mediated electrostatic interactions, and π-conjugation design to promote highly ordered J-aggregation. The optimized dye, IRJ1089, assembles into remarkably stable and encapsulation-free J-aggregates, exhibiting high optoacoustic signal generation efficiency and ultra-narrowband absorption at 1089 nm with a FWHM of 164 cm-1 (19.4 nm). Based on a structural analogue's (IRJ1021) crystallographic data and computational analyses, we propose that electrostatic interlocking between sulfonate groups and the polarized π-backbone, together with favorable slip-stacking geometry, promotes aggregate order and enhances the J-aggregates' stability. IRJ1089 J-aggregates support high-contrast multispectral optoacoustic tomography (MSOT) imaging in vasculature deep inside rats (∼1.2 cm), enable real-time monitoring of antihypertensive drug-induced aortic dilation, and allow crosstalk-free SWIR multiplexed imaging for diagnosing colorectal cancer-associated intestinal obstruction. These findings establish a generalizable blueprint for designing ultra-narrowband J-aggregating dyes and provide valuable insights into other SWIR photonic materials in multiple areas.
The metal-organic framework UTSA-16, based on K+, Co2+, and citrate as the organic linker and first reported in 2005, is one of the most attractive candidates as a solid adsorbent for postcombustion CO2 capture. Here, we revisit the crystal structure of UTSA-16 on the basis of clear evidence that the amount of potassium has been systematically underestimated in previous literature reports dealing with crystallographic characterization. By combining CHN elemental analysis, inductively coupled plasma optical emission spectroscopy, and thermogravimetric analysis, we find that the actual chemical formula for UTSA-16 is K2Co3(cit)2·8H2O, with a K/Co ratio twice as large as the one assumed in previous literature. Single crystal X-ray diffraction analysis leads to identifying two extraframework positions occupied by previously overlooked K+ ions, which are likely to play a key role in the adsorption behavior of UTSA-16.
Expanding the scope of isoreticular chemistry to include chiral ligands remains a fundamental challenge, particularly for high-symmetry framework topologies that generally favor symmetry matching between building blocks and the crystallographic sites they occupy. Here, we demonstrate that the partitioned acs (pacs) platform can accommodate a chiral dicarboxylate ligand, (1R,3S)-(+)-camphoric acid (d-cam), representing the first pacs MOF constructed from a chiral L1 ligand. The successful assembly of the framework is enabled by the cooperative structure-directing effects of a tripyridyl pore-partitioning ligand and heterometallic Co/In trinuclear clusters, which collectively enforce alignment of ligand coordination vectors while permitting subtle charge and size tunability through variable Co2+/In3+ ratios within the trimers. Structural analysis reveals that the framework preserves the characteristic pacs architecture despite geometric distortion arising from the stereochemical features and low symmetry of the ligand. These results suggest that geometric mismatch is redistributed throughout the framework through cooperative distortion of ligand orientation, cage geometry, and trimer coordination environment. Gas sorption studies reveal preferential adsorption of C2H2 over CO2, while breakthrough experiments demonstrate stable C2H2/CO2 separation over multiple cycles. More broadly, this work suggests that cooperative multimodule assembly can relax classical symmetry-matching constraints in isoreticular chemistry.
The diversity of protein structures and reaction mechanisms complicates general-purpose artificial intelligence models for enzyme engineering, motivating family-specialized models. In this study, we developed EnzFormer, a specialized artificial intelligence pipeline for engineering Staphylococcus aureus L-cystathionine gamma-lyase (SaMccB). To overcome the scarcity of experimental labels, we used GPT-4o to generate putative activity labels for cystathionine gamma-lyase homologs, leveraging species-level ecological and evolutionary metadata as a proxy for functional selection. Using these labels, we trained a Transformer classifier on embeddings from the ESM Cambrian protein language model. From an exhaustive single-mutant library, in silico prioritization nominated 4 variants for testing and identified SaMccB V129G with a ~2-fold increase in catalytic turnover relative to the wild type. Val129 is distal to the active site; crystallographic and biochemical analyses suggest that V129G weakens local packing, thereby increasing the conformational flexibility of the active site loop, consistent with faster conformational steps in the catalytic cycle. Together, these results suggest that combining large language model-derived evolutionary priors with a family-specialized predictive model can identify distal mutations that modulate enzyme dynamics.
In the title solvate, C6H6N2O·0.5C2H6O2, the asymmetric unit consists of one nicotinamide mol-ecule and half of an ethyl-ene glycol mol-ecule, which is completed by crystallographic inversion symmetry. The dihedral angle between the acetamide group and the pyridine ring is 21.9 (8)°. In the crystal, the components are linked by N-H⋯O and O-H⋯N hydrogen bonds into (102) sheets and weak offset π-π stacking is also observed. Hirshfeld surface analysis indicates that the most important contacts in the structure are H⋯H (42.9%), O⋯H/H⋯O (26.4%), C⋯H/H⋯C (10.6%) and N⋯H/H⋯N (9.2%).
The title compound, di-aquabis-{2-formyl-6-meth-oxy-4-[(E)-2-phenyl-diazen-1-yl]phenolato-κ2 O 1,O 2}iron(II), [Fe(C14H11N2O3)2(H2O)2], comprises two bi-dentate ligands derived from 2-meth-oxy-4-(phenyl-diazen-yl)-6-formyl-phenol and two coordinated water mol-ecules. The FeII center is located at a crystallographic inversion center and adopts an octa-hedral coordination geometry. Both azo-phenolate ligands coordinate in a bidentate chelating mode (κ2 O,O') through the phenolate oxygen and formyl oxygen atoms in a centrosymmetric arrangement. The crystal structure was determined at 79 K using the MicroED method (λ = 0.02508 Å). The complex crystallizes in the monoclinic space group P21/n with Z = 2. The azo groups adopt trans conformations. A Hirshfeld surface analysis indicates that the most important contributions to the packing are from H⋯H (36.8%) and C⋯H/H⋯C (31.9%) contacts.
Structural disorder usually plays a decisive role in determining the functional properties of crystalline materials, yet it remains difficult to characterize, particularly at the micro- and nanometer scales. Three-dimensional electron diffraction (3D ED) provides access to crystallographic information from single crystals far smaller than those required for X-ray or neutron diffraction. However, its application has remained largely confined to average structure determination, where subtle and spatially diffuse electron density features associated with disorder are commonly obscured by truncation artifacts, model bias, and limitations inherent to the conventional Fourier method. Here, we develop a maximum entropy method-based electron density reconstruction framework specifically adapted for 3D ED (3D ED-MEM), enabling quantitative, model-independent electron density mapping directly from submicron crystals. By integrating electron diffraction-specific structure factors extraction and transformation procedures, this approach overcomes intrinsic limitations of the Fourier method and extends the capability of 3D ED to high-fidelity electron density analysis. Benchmarking against synchrotron X-ray diffraction using Si demonstrates that 3D ED-MEM yields electron density distributions of comparable accuracy. The generality of this approach is further validated using two archetypical structurally disordered thermoelectric materials, where 3D ED-MEM resolves trace interstitial ions and continuous ionic migration pathways. By enabling high quality electron density reconstruction from submicron crystals, 3D ED-MEM uniquely complements established diffraction techniques and is particularly powerful for materials where large single crystals cannot be grown and phase-pure powders are difficult to obtain, establishing a broadly applicable tool for probing disorder and dynamics in functional materials.
Four-dimensional scanning transmission electron microscopy (4D-STEM) enables mapping of diffraction information with nanometer-scale spatial resolution, offering detailed insight into local structure, orientation, and strain. However, as data dimensionality and sampling density increase, particularly for in situ scanning diffraction experiments (5D-STEM), robust segmentation of structurally consistent behavior across sequential measurements becomes essential for efficient and physically meaningful analysis. Here, we introduce a clustering framework that identifies crystallographically distinct domains from 4D-STEM datasets. By using local diffraction-pattern similarity as a metric, the method extracts closed contours delineating spatially contiguous regions. This approach produces cluster-averaged diffraction patterns that improve signal quality while reducing data volume by orders of magnitude, enabling rapid and accurate orientation, phase, and strain mapping. We demonstrate the applicability of this approach to in situ liquid-cell 4D-STEM data of gold nanoparticle growth. Our method provides a scalable and generalizable route for spatially coherent segmentation, data compression, and quantitative structure-strain mapping across diverse 4D-STEM modalities. The full analysis code and example workflows are publicly available to support reproducibility and reuse.
This work describes the synthesis, characterization, and preliminary evaluation of the anti-Plasmodium falciparum activity of a copper(II) coordination-complex derived from an imidazole-based ligand. This compound was characterized by Infrared, UV-Vis, Raman, high resolution mass spectrometry, fluorescence, Thermogravimetric analysis, and electrical conductivity allowing the elucidation of their structure and which was also confirmed by single-crystal X-ray diffraction. From the crystallographic analysis, it was found that the copper atom is situated in an octahedral environment, with both carboxylate ligands occupying equatorial positions and the ligands L located axially. Interestingly, the acetate ions act as bidentate ligands, but in an anisobidentate binding mode, where the oxygen atoms exhibit different bond distances to the metal center, resulting in asymmetric coordination. This phenomenon is attributed to strong hydrogen bonding within the crystal packing. Biological assays performed to test the complex revealed low hemocytotoxicity, with values ≤20% at concentrations above 500 µg/mL. When evaluated in vitro against Plasmodium falciparum (3D7 strain, chloroquine-sensitive), the complex exhibited significantly higher activity than the free ligand. These findings indicate that coordination to the metal center plays a substantial role in enhancing antiparasitic-activity, providing a solid foundation for future investigations aimed at elucidating the underlying mechanisms and advancing research on the anti-Plasmodium falciparum activity of metal complexes.
Elastic mechanoluminescent (ML) materials have significant potential in intelligent sensing, dynamic displays, and artificial intelligence. However, concrete experimental evidence of localized piezoelectric fields has long been missing in piezoelectrically controlled elastic ML materials. In this work, we propose a strategy for uncovering the local piezoelectric field effect in ML materials and demonstrate that crystallographic site symmetry and local structure determine the local piezoelectric field, which further profoundly influences the ML properties of the material. We screen and design multisite deep‑red to near‑infrared (NIR) self‑recoverable ML materials, Mn2+-activated MGa2S4 (M = Ca, Sr). Beyond the report of ultrabroadband ML performance, we have defined and calculated, for the first time, the centrosymmetry deviation degree (CDD) of a polyhedron, and elucidated the correlation among site symmetry, CDD, polyhedral distortion degree, local piezoelectric responses, and ML intensity. With the assistance of DFT and DFPT calculations, we have clarified the contribution of local polarization at specific sites and established a dynamic model for local‑piezoelectric‑field‑induced ML in multisite materials. Furthermore, leveraging the ultrabroadband ML emission of this material series, we fabricated various flexible devices, which demonstrated promising application potential in fields such as rehabilitation medicine, deep-tissue bioimaging, and NIR information encryption. This work holds potential to offer valuable insights for discovering, designing, and yielding novel ML materials.
In our ongoing research into Tomato spotted wilt virus (TSWV) inhibitors derived from natural products, a comprehensive phytochemical analysis of the whole plant of Andrographis paniculata was performed. This study afforded 29 labdane diterpenoids (1-29), including eight previously unreported compounds (1-8). Among these, compound 2 features an uncommon 6/6/5 tricyclic scaffold, while compound 5 possesses a distinct 6/6/6/5 tetracyclic framework. The structures of isolated compounds were unequivocally determined via NMR, HRESIMS, IR, UV, quantum chemical calculations, and X-ray crystallographic analysis. In anti-TSWV assays, compound 9 exhibited stronger protective activity (EC50: 100.7 μg/mL) than the positive control ningnanmycin (EC50: 107.5 μg/mL). Mechanistic studies, including RNA-sequencing analysis, revealed that compound 9 activates both the photosynthetic and salicylic acid pathways, enhances systemic acquired resistance, and thereby suppresses TSWV replication. This study offers valuable molecular leads and conceptual insights for the development of novel pesticides.