Search Results (225)

This work reports the crystallographic study of two benzenesulfonamides, 1 ((E)-N-benzyl-3-((benzylimino)methyl)-4-hydroxybenzenesulfonamide) and 2 (N-benzyl-3-(3-(N-benzylsulfamoyl)-2-oxo-2H-chromene-6-sulfonamide). These compounds share structural features with belinostat, an FDA-approved histone deacetylase (HDAC) inhibitor used in the treatment of peripheral T-cell lymphoma. Compound 1 contains one sulfonamide group, meanwhile compound 2 contains two sulfonamide moieties and presents four independent molecules in its unit cell. The crystal packing of 1 and 2 is mainly governed by N–H···O=S hydrogen bonding interactions. π → π* and n → π* stacking interactions also contribute to the molecular assembly. Hirshfeld surface (HS) analysis was carried out to further examine the intermolecular interactions of compounds 1 and 2, revealing that N–H∙∙∙O and C–H∙∙∙O hydrogen bonding interactions, along with O∙∙∙H/H∙∙∙O interactions, are the strongest contributors to the individual surfaces. Interaction energy analysis was also performed to evaluate the relative strength and nature of the intermolecular contacts. Additionally, molecular docking studies of compounds 1 and 2 were performed on the crystal structure of the enzyme HDAC2, an enzyme overexpressed in several cancers, particularly breast cancer. The results revealed that both compounds exhibit a binding mode and binding energies similar to those of belinostat, suggesting their potential as novel therapeutic agents. Full article

The intrinsic structural stability of ABO₃ perovskite materials is a pivotal factor determining their efficiency and durability in photovoltaic applications. However, accurately predicting stability, commonly measured by the energy above hull metric, remains challenging due to the complex interplay of compositional, crystallographic, and electronic features. To address this challenge, we propose a streamlined hybrid machine learning framework that combines the sequence modeling capability of Long Short-Term Memory (LSTM) networks with the robustness of Random Forest regressors. A genetic algorithm-based feature selection strategy is incorporated to identify the most relevant descriptors and reduce noise, thereby enhancing both predictive accuracy and interpretability. Comprehensive evaluations on a curated ABO₃ dataset demonstrate strong performance, achieving an $R^2$ of 0.98 on training data and 0.83 on independent test data, with a Mean Absolute Error (MAE) of 8.78 for training and 21.23 for testing, and Root Mean Squared Error (RMSE) values that further confirm predictive reliability. These results validate the effectiveness of the proposed approach in capturing the multifactorial nature of perovskite stability while ensuring robust generalization. This study highlights a practical and reliable pathway for accelerating the discovery and optimization of stable perovskite materials, contributing to the development of more durable next-generation solar technologies. Full article

Owing to the differences in crystallographic orientations among individual grains, dislocation structures in polycrystals are inherently inhomogeneous from grain to grain. Since intergranular incompatibility is inevitable during plastic deformation, it may consequently lead to unpredictable plastic strain localization, which in turn facilitates the initiation of fatigue crack. Therefore, to elucidate the mechanisms underlying inhomogeneous deformation in polycrystals, this study systematically examines the fatigue-induced dislocation structures in polycrystalline SUS316L stainless steel. We then directly compare them with those in copper single crystals to clarify the dependence of the dislocation structures on crystallographic orientation. SEM characterization demonstrates that high plastic strain near grain boundaries promotes the formation of secondary cell bands (CBs) overlapping the primary CBs, which is attributable to the simultaneous activation of multiple-slip systems under high plastic strain amplitudes. In addition to strain localization, competition among candidate secondary slip systems strongly governs the dislocation structures. Notably, a new type of deformation band (DB) on the (010) plane is identified in a non-coplanar double-slip-oriented grain, a feature not observed in single crystals, indicating that polycrystals accommodate plastic strain through distinct mechanisms. Detailed dislocation structure analysis provides theoretical guidance for mitigating fatigue crack initiation through the manipulation of dislocations. Full article

Silver is a promising electrocatalyst for electrochemical CO₂ reduction reaction owing to its high selectivity and efficiency for CO production. However, it still faces a fundamental trade-off between reaction activity and stability. Here, we developed a three-dimensional coral-like porous silver (CP-Ag) catalyst through seed-assisted nanoparticle attachment synthesis, which creates a unique architecture featuring interconnected pores and stable grain boundaries (GBs) between constituent Ag nanoparticles (Ag NPs). Compared to normal Ag NPs, CP-Ag demonstrates superior catalytic performance, maintaining >90% Faradaic efficiency (FE) for CO across a wide potential range (−0.6 to −1.0 V vs. RHE) while achieving 2-times higher current density. Importantly, CP-Ag demonstrated an impressive long-term stability by sustaining nearly 90% FE for CO approximately 40 h at a current density of −50 mA cm⁻² in a flow cell. The enhanced catalytic performance arises from three factors: (1) the three-dimensional coral-like morphology increases accessible active sites and promotes charge transfer efficiency; (2) stable GBs between interconnected nanoparticles increase reaction activity; (3) more moderate binding on Ag (100) preferentially promotes *CO intermediate formation. Our findings highlight the importance of simultaneously engineering both morphological and crystallographic features to optimize silver catalysts for CO₂ conversion. Full article

d-Tagatose, classified as a rare sugar, exhibits notable biological activities, including its function as a low-calorie sweetener. The three-dimensional configuration of carbohydrates is crucial for elucidating their functional properties. Numerous studies have reported the X-ray crystallographic structures of d-tagatose and its derivatives bearing a free anomeric hydroxy group. However, there are no reports on the X-ray crystallographic structure of d-tagatosides featuring a glycosidic linkage at the anomeric position. In this study, we synthesized methyl α-d-tagatopyranoside from d-tagatose and successfully determined its X-ray crystallographic structure, revealing its ⁵C₂ conformation. Full article

This study investigates the hot deformation behaviour and microstructural evolution of two AISI 430 ferritic stainless steel variants: 0A (basic) and 1C (modified). These variants primarily differ in chemical composition, with 0A containing higher austenite-stabilizing elements (C, N) compared to 1C, which features lower interstitial content and slightly higher Si and Cr. This research aimed to optimize hot rolling conditions for enhanced forming properties. Uniaxial hot compression tests were conducted using a Gleeble thermo-mechanical system between 850 and 990 °C at a strain rate of 3.3 s⁻¹, simulating industrial finishing mill conditions. Analysis of flow curves, coupled with detailed microstructural characterization using electron backscatter diffraction, revealed distinct dynamic restoration mechanisms influencing each material’s response. Thermodynamic simulations confirmed significant austenite formation in both materials within the tested temperature range, notably affecting their deformation behaviour despite their initial ferritic state. Material 0A consistently exhibited a strong tendency towards dynamic recrystallization (DRX) across a wider temperature range, particularly at 850 °C. DRX led to a microstructure with a high concentration of low-angle grain boundaries and sharp deformation textures, actively reorienting grains towards energetically favourable configurations. However, under this condition, DRX did not fully complete the recrystallization process. In contrast, material 1C showed greater activity of both dynamic recovery and DRX, leading to a much more advanced state of grain refinement and recrystallization compared to 0A. This indicates that the composition of 1C helps mitigate the strong influence of the deformation temperature on the crystallographic texture, leading to a weaker texture overall than 0A. Full article

Arginine kinase is a key phosphagen kinase in invertebrates that facilitates rapid ATP regeneration by reversibly transferring phosphate groups between phosphoarginine and ADP. Structural studies have shown that the enzyme adopts distinct conformations in its ligand-free and ligand-bound states, known as the “open” and “closed” forms, respectively. These conformational changes are crucial for catalytic activity, enabling precise positioning of active-site residues and loop closure during phosphoryl transfer. Transition-state analog complexes have provided additional insights by mimicking intermediate states of catalysis, supporting the functional relevance of the open/closed structural model. Furthermore, studies across multiple species reveal how monomeric and dimeric forms of arginine kinase contribute to its allosteric regulation and substrate specificity. Beyond its metabolic role, arginine kinase is also recognized as a major allergen in crustaceans. Its structural uniqueness and absence in vertebrates make it a promising candidate for selective drug targeting. By integrating crystallographic data with functional context, this review highlights conserved features and species-specific variations of arginine kinase that may inform the design of inhibitors. Such molecules have the potential to serve both as antiparasitic agents and as novel therapeutics to manage crustacean-related allergic responses in humans. Full article

In this work, the microstructure and mechanical properties of the FeAlCrNiV complex concentrated alloy (CCA) were studied in the as-cast and annealed states. The material was annealed at 800 °C for 16 days to test microstructure stability and phase evolution. It was found that the microstructure does not differ in the two investigated states, and the results of differential scanning calorimetry and dilatometry showed that there is almost no difference in the thermal response between the as-cast and annealed states. Both investigated states exhibit eutectic structure with bcc solid solution and ordered phase with B2 symmetry. In a single grain, several regions with B2 laths in the bcc matrix were observed. Inside the B2 laths and in the bcc matrix, bcc spheres and B2 spheres were observed, respectively. All three features—laths, matrix and spheres—are fully crystallographically coherent. Nevertheless, in the adjacent region in the grain, the crystal structure of the matrix, laths and sphere changed to the other structure, i.e., the characteristics of the microstructure feature with B2 symmetry changed to bcc, and vice versa. Compression deformation tests were performed for various temperatures from room temperature to 800 °C. The results showed that the material exhibits exceptional yield stress values, especially at high temperatures (820 MPa/800 °C), and excellent plasticity (25%). Full article

This study proposes a coupled constitutive model that captures the anisotropic failure characteristics and damage evolution of nickel-based single-crystal (SX) superalloys under various temperature conditions. The model accounts for both creep rate and material damage evolution, enabling accurate prediction of the typical three-stage creep curves, macroscopic fracture morphologies, and microstructural features under uniaxial tensile creep for specimens with different crystallographic orientations. Creep behavior of SX superalloys was simulated under multiple orientations and various temperature-stress conditions using the proposed model. The resulting creep curves aligned well with experimental observations, thereby validating the model’s feasibility and accuracy. Furthermore, a finite element model of cylindrical specimens was established, and simulations of the macroscopic fracture morphology were performed using a user-defined material subroutine. By integrating the rafting theory governed by interfacial energy density, the model successfully predicts the rafting morphology of the microstructure at the fracture surface for different crystallographic orientations. The proposed model maintains low programming complexity and computational cost while effectively predicting the creep life and deformation behavior of anisotropic materials. The model accurately captures the three-stage creep deformation behavior of SX specimens and provides reliable predictions of stress fields and microstructural changes at critical cross-sections. The model demonstrates high accuracy in life prediction, with all predicted results falling within a ±1.5× error band and an average error of 14.6%. Full article

The transition to clean and renewable energy sources is critically dependent on efficient hydrogen production technologies. This review surveys recent advances in photocatalytic water splitting, focusing on MNb₂O₆ nanomaterials, which have emerged as promising photocatalysts due to their tunable band structures, chemical robustness, and tailored morphologies. The objectives of this work are to (i) encompass the current synthesis strategies for MNb₂O₆ compounds; (ii) assess their structural, electronic, and optical properties in relation to photocatalytic performance; and (iii) elucidate the mechanisms underpinning enhanced hydrogen evolution. Main data collection methods include a literature review of experimental studies reporting bandgap measurements, structural analyses, and hydrogen production metrics for various MNb₂O₆ compositions—especially those incorporating transition metals such as Mn, Cu, Ni, and Co. Novelty stems from systematically detailing the relationships between synthesis routes (hydrothermal, solvothermal, electrospinning, etc.), crystallographic features, conductivity type, and bandgap tuning in these materials, as well as by benchmarking their performance against more conventional photocatalyst systems. Key findings indicate that MnNb₂O₆, CuNb₂O₆, and certain engineered heterostructures (e.g., with g-C₃N₄ or TiO₂) display significant visible-light-driven hydrogen evolution, achieving hydrogen production rates up to 146 mmol h⁻¹ g⁻¹ in composite systems. The review spotlights trends in heterojunction design, defect engineering, co-catalyst integration, and the extension of light absorption into the visible range, all contributing to improved charge separation and catalytic longevity. However, significant challenges remain in realizing the full potential of the broader MNb₂O₆ family, particularly regarding efficiency, scalability, and long-term stability. The insights synthesized here serve as a guide for future experimental investigations and materials design, advancing the deployment of MNb₂O₆-based photocatalysts for large-scale, sustainable hydrogen production. Full article

As renewable energy technologies advance, identifying efficient photocatalytic materials for water splitting to produce hydrogen has become an important research focus in materials science. This study presents a multi-task regression model (MTRM) designed to predict the conduction band minimum (CBM), valence band maximum (VBM), and solar-to-hydrogen efficiency (STH) of inorganic materials. Utilizing crystallographic and band gap data from over 15,000 materials in the SNUMAT database, machine-learning methods are applied to predict CBM and VBM, which are subsequently used as additional features to estimate STH. A deep neural network framework with a multi-branch, multi-task regression structure is employed to address the issue of error propagation in traditional cascading models by enabling feature sharing and joint optimization of the tasks. The calculated results show that, while traditional tree-based models perform well in single-task predictions, MTRM achieves superior performance in the multi-task setting, particularly for STH prediction, with an MSE of 0.0001 and an R² of 0.8265, significantly outperforming cascading approaches. This research provides a new approach to predicting photocatalytic material performance and demonstrates the potential of multi-task learning in materials science. Full article

This study investigates the factors affecting the mechanical performance of conventional and impulse friction stir welded (FSW and IFSW) AA2024-T351 joints under static and cyclic loading. Emphasis is placed on the influence of fracture-inducing features such as oxide inclusions, constituent particle distributions, crystallographic texture, and precipitation state. A series of IFSW welds produced at varying impulse parameters were compared to conventional FSW welds in terms of microhardness, tensile strength, fatigue life, and Taylor factor distribution. IFSW joints demonstrated a significant improvement in tensile strength and elongation, particularly at higher impulse frequencies. Enhanced material mixing due to the reciprocating tool motion in IFSW resulted in finer particle distribution, more favorable crystallographic texture, and reduced weld pitch, all contributing to increased ductility and strength. Fractographic analyses revealed that fatigue failures primarily initiated in the stir zone, typically at unplasticized metallic inclusions. However, IFSW joints displayed longer fatigue lives, particularly when impulse parameters were optimized. These findings underline the complex interplay of microstructural and textural factors in determining weld performance, highlighting IFSW as a promising technique for enhancing the durability of high-strength aluminum welds. Full article

CrystalShift is an open-source computational tool tailored for the analysis, transformation, and conversion of crystallographic data, with a particular emphasis on organic crystal structures. It offers a comprehensive suite of features valuable for the computational study of solids: format conversion, crystallographic basis transformation, atomic coordinate editing, and molecular layer analysis. These options are especially valuable for studying the mechanical properties of molecular crystals with potential applications in organic materials science. Written in the C programming language, CrystalShift offers computational efficiency and compatibility with widely used crystallographic formats such as CIF, POSCAR, and XYZ. It provides a command-line interface, enabling seamless integration into research workflows while addressing specific challenges in crystallography, such as handling non-standard file formats and robust error correction. CrystalShift may be applied for both in-depth study of particular crystal structure origins and the high-throughput conversion of crystallographic datasets prior to DFT calculations with periodic boundary conditions using VASP code. Full article

This article presents the single-crystal structure of the complex salt sodium dithiocuprate(I) dodecahydrate Na₃CuS₂·12(H₂O), i.e., [Na₃(H₂O)₁₂][CuS₂], which forms in the high-sulfide concentrations of the alkaline solutions used for arsenic separation from copper concentrates. It features a linear hydrogen-bonded dithiocuprate(I) anion, a novelty in crystallographically characterized thiocuprates. During the study of the alkaline sulfide leaching of Chilean copper concentrates, an analytical investigation of the solution led to the detection of this complex. This study aimed to understand the chemical behavior of the leaching solution by identifying existing ions, which facilitated the discovery of the complex using single-crystal analysis. The newly discovered complex was also synthesized from a modeling solution based on the leaching solution recipe for arsenic removal, allowing for further crystal characterization through Raman and XRD analysis. By estimating the sodium sulfide threshold concentration that enhanced the formation of the copper disulfide complex, this study defined the upper technical threshold limit of sulfide concentration for the economic development of alkaline sulfide leaching to remove arsenic. Full article

Imidazoline I₂ receptors (I₂-IR) are untapped therapeutic targets lacking a structural description. Although the levels of I₂-IR are dysregulated in a plethora of illnesses, the arsenal of ligands that can modulate I₂-IR is limited. In this framework, we have reported several new structural families embodying the iminophosphonate functional group that have an excellent affinity and selectivity for I₂-IR, and selected members have demonstrated relevant pharmacological properties in murine models of neurodegeneration and Alzheimer’s disease. Starting with these iminophosphonates, we continued to exploit their high degree of functionalization through a short and efficient synthesis to access unprecedented 2,3-di, 2,2,3-tri, 2,3,4-tri, and 2,2,3,4-tetrasubstituted diethyl (pyrrolidine-2-yl) phosphonates. The stereochemistry of the new compounds was unequivocally characterized by X-ray crystallographic analyses. Two selected compounds with structural features shared with the starting products were pharmacologically evaluated, allowing us to deduce the required key structural motifs for biologically active aminophosphonate derivatives. Full article