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In the past decade, natural orbital functional (NOF) approximations have emerged as prominent tools for characterizing electron correlation. Despite their effectiveness, these approaches, which rely on natural orbitals and their associated occupation numbers, often require hybridization with other methods to fully account for all correlation effects. Recently, a global NOF (GNOF) has been proposed [Piris, Phys. Rev. Lett. 127, 233001 (2021)] to comprehensively address both dynamic and static correlations. This study evaluates the performance of GNOF on strongly correlated model systems, including comparisons with highly accurate Full Configuration Interaction calculations for hydrogen atom clusters in one, two, and three dimensions. Additionally, the investigation extends to a BeH2 reaction, involving the insertion of a beryllium atom into a hydrogen molecule along a C2v pathway. According to the results obtained using GNOF, consistent behavior is observed across various correlation regions, encompassing a range of occupations and orbital schemes. Furthermore, distinctive features are identified when varying the dimensionality of the system. [ABSTRACT FROM AUTHOR]

We describe a method to compute photon–matter interaction and atomic dynamics with x-ray lasers using a hybrid code based on classical molecular dynamics and collisional-radiative calculations. The forces between the atoms are dynamically determined based on changes to their electronic occupations and the formation of a free electron cloud created from the irradiation of photons in the x-ray spectrum. The rapid transition from neutral solid matter to dense plasma phase allows the use of screened potentials, reducing the number of non-bonded interactions. In combination with parallelization through domain decomposition, the hybrid code handles large-scale molecular dynamics and ionization. This method is applicable for large enough samples (solids, liquids, proteins, viruses, atomic clusters, and crystals) that, when exposed to an x-ray laser pulse, turn into a plasma in the first few femtoseconds of the interaction. We present four examples demonstrating the applicability of the method. We investigate the non-thermal heating and scattering of bulk water and damage-induced dynamics of a protein crystal using an x-ray pump–probe scheme. In both cases, we compare to the experimental data. For single particle imaging, we simulate the ultrafast dynamics of a methane cluster exposed to a femtosecond x-ray laser. In the context of coherent diffractive imaging, we study the fragmentation as given by an x-ray pump–probe setup to understand the evolution of radiation damage in the time range of hundreds of femtoseconds. [ABSTRACT FROM AUTHOR]

The crystal orientation and the temperature of the substrate are crucial factors that influence clusters deposition and, consequently, the properties of thin films. In this study, the molecular dynamics simulation method was employed to investigate the deposition of Cu55 clusters on Fe(001), Fe(011), and Fe(111) substrates with varying crystal orientations. The incident energies used ranged from 0.1 to 20.0 eV/atom, and the substrates were maintained at temperatures of 300, 500, and 800 K. Analysis of cluster and substrate atom snapshots, along with the physical properties of clusters, revealed how the crystal orientation of Fe substrates affects the morphology and structure of the cluster at different temperatures. Additionally, specific microscopic mechanisms responsible for these effects were identified. The simulation results demonstrate that the crystal orientation of Fe substrate significantly influences the deposition of Cu55 clusters. The structures of the clusters on the three crystal substrates undergo similar changes as the substrate temperature increases, with the Cu55 clusters on the Fe(111) substrate exhibiting the most significant changes in response to the temperature rise. [ABSTRACT FROM AUTHOR]

31P nuclear magnetic resonance (NMR) chemical shifts were shown to be very sensitive to the basis set used at the geometry optimization stage. Commonly used energy-optimized basis sets for a phosphorus atom containing only one polarization d-function were shown to be unable to provide correct equilibrium geometries for the calculations of phosphorus chemical shifts. The use of basis sets with at least two polarization d-functions on a phosphorus atom is strongly recommended. In this paper, an idea of creating the basis sets purposed for the geometry optimization that provide the least possible error coming from the geometry factor of accuracy in the resultant NMR shielding constants is proposed. The property-energy consisted algorithm with the target function in the form of the molecular energy gradient relative to P–P bond lengths was applied to create new geometry-oriented pecG-n (n = 1, 2) basis sets for a phosphorus atom. New basis sets have demonstrated by far superior performance as compared to the other commonly used energy-optimized basis sets in massive calculations of 31P NMR chemical shifts carried out at the gauge-including atomic orbital-coupled cluster singles and doubles/pecS-2 level of the theory by taking into account solvent, vibrational, and relativistic corrections. [ABSTRACT FROM AUTHOR]

Thermal transport in wurtzite aluminum nitride (w-AlN) significantly affects the performance and reliability of corresponding electronic devices, particularly when lattice strains inevitably impact the thermal properties of w-AlN in practical applications. To accurately model the thermal properties of w-AlN with high efficiency, we develop a machine learning interatomic potential based on the atomic cluster expansion (ACE) framework. The predictive power of the ACE potential against density functional theory (DFT) is demonstrated across a broad range of properties of w-AlN, including ground-state lattice parameters, specific heat capacity, coefficients of thermal expansion, bulk modulus, and harmonic phonon dispersions. Validation of lattice thermal conductivity is further carried out by comparing the ACE-predicted values to the DFT calculations and experiments, exhibiting the overall capability of our ACE potential in sufficiently describing anharmonic phonon interactions. As a practical application, we perform a lattice dynamics analysis using the potential to unravel the effects of biaxial strains on thermal conductivity and phonon properties of w-AlN, which is identified as a significant tuning factor for near-junction thermal design of w-AlN-based electronics. [ABSTRACT FROM AUTHOR]

Nanoscale magnesium clusters are important potential hydrogen storage materials, and density functional theory (DFT) is mainly used for their theoretical investigation. The results of the coupled-cluster theory at the singles and doubles level with a perturbative treatment of triples [CCSD(T)] were employed previously to choose proper exchange–correlation (XC) functionals in DFT calculations for magnesium clusters, but it is too expensive to be applied to Mgn with n > 7. The diffusion Monte Carlo (DMC) method is employed in this work to study magnesium clusters up to nanosize. The error of atomization energies with DMC using single-determinant-Jastrow (SDJ) trial wavefunctions has been shown to be somewhat larger than that of CCSD(T) for many molecules. However, cohesive energies with DMC using SDJ for Mgn with n ≤ 7 are in excellent agreement with those of CCSD(T) using the aug-cc-pVQZ basis set, with a difference of less than 1 kcal/mol. DMC results are employed to investigate the performance of different XC functionals on magnesium clusters. Our results indicate that the PBE0 functional is the best XC functional for determining the lowest-energy isomer when compared with DMC results, while the RPBE functional is the best XC functional for calculating cohesive energies per atom of these magnesium clusters with a mean absolute error of 0.5 kcal/mol. These XC functionals are expected to provide reasonable results for even larger magnesium clusters. [ABSTRACT FROM AUTHOR]

We introduce ACEpotentials.jl, a Julia-language software package that constructs interatomic potentials from quantum mechanical reference data using the Atomic Cluster Expansion [R. Drautz, Phys. Rev. B 99, 014104 (2019)]. As the latter provides a complete description of atomic environments, including invariance to overall translation and rotation as well as permutation of like atoms, the resulting potentials are systematically improvable and data efficient. Furthermore, the descriptor's expressiveness enables use of a linear model, facilitating rapid evaluation and straightforward application of Bayesian techniques for active learning. We summarize the capabilities of ACEpotentials.jl and demonstrate its strengths (simplicity, interpretability, robustness, performance) on a selection of prototypical atomistic modelling workflows. [ABSTRACT FROM AUTHOR]

The unique physical properties of carbyne, a novel carbon nanostructure, have attracted considerable interest in modern nanotechnology. While carbyne synthesis has been accomplished successfully using diverse techniques, the underlying mechanisms governing the carbon monoxide-dependent catalytic synthesis of endohedral carbyne remain poorly understood. In this simulation-based study, we investigate the synthesis of endohedral carbyne from carbon and carbon monoxide radicals in the presence of a nickel catalyst inside double-walled carbon nanotubes with a (5,5)@(10,10) structure. The outcome of our investigation demonstrates that the incorporation of the carbon atom within the Nin@(5,5)@(10,10) model system initiates the formation of an elongated carbon chain. In contrast, upon the introduction of carbon monoxide radicals, the growth of the carbyne chain is inhibited as a result of the oxidation of endohedral nickel clusters by oxygen atoms after the initial steps of nucleation. Our findings align with prior theoretical, simulation, and experimental investigations, reinforcing their consistency and providing valuable insights into the synthesis of carbyne-based nanodevices that hold promising potential for future advancements in nanotechnology. [ABSTRACT FROM AUTHOR]

High pressure has been recognized as an important tool in molecule and materials research, and thus, it is expected to be used to understand the evolution of electronic states and geometric structures in superatoms. In this work, by studying three characteristic axial compressions on a typical endohedral metallofullerene superatom U@C28 with Td symmetry, we find that the triplet ground electronic state is preserved when the compression moves along the direction that reduces the symmetry to D2d, but the electronic state of the structure compressed along the direction of symmetry reduction to C2v or Cs is transformed into a singlet. The transition is attributed to the distinction in the response of electron spin to different axial compressions, which results in a change in the electron occupation mode of the system. Furthermore, we also confirm the gradual evolution from stereo to near-plane superatoms and the connection between their electron structures. This is reflected in the fact that the electron density distributions of the superatomic molecular orbitals (SAMOs) with extension along the restricted degrees of freedom ( D z 2 , F z 3 SAMOs) gradually contract, and the delocalization destruction of special orbitals is associated with this freedom. In addition, Raman and ultraviolet–visible spectra show a hyperchromic effect and redshift of characteristic peaks during axial compression, which are expected to be used for fingerprinting the superatomic planarization. Therefore, our work provides new insights based on high pressure for future research toward the discovery of physical properties and applications of superatoms. [ABSTRACT FROM AUTHOR]

Simultaneously improving activity and stability is a crucial yet challenge in the development of metallic single‐atom‐based catalysts. In current work, a novel approach is introduced to address this issue by combining post‐adsorption and secondary pyrolysis techniques to create a synergistic catalytic system, in which the single atoms (SAs) Fe sites played in the NC matrix (Fe─NC) are coupled with high‐entropy atomic clusters (HEACs). Theoretical calculations reveal that the incorporation of HEACs lead to a rehybridization of the 3d orbital configuration of Fe‐N4, which helps to balance the adsorption/desorption energy of oxygenated intermediates. In situ spectroscopy further reveals that the rate‐limiting step of OH* desorption on HEAC/Fe─NC in oxygen reduction reaction (ORR) is more facile compared to atomic Fe─NC, implying a higher ORR activity. Moreover, the synergistic effect of diffusion activation barriers and configuration entropy contributes to the structural stability of HEAC/Fe─NC, resulting in remarkable durability. Consequently, this unique catalyst exhibits half‐wave potentials of 0.927 and 0.828 V in an aqueous solution of KOH (0.1 m) and HClO4 (0.1 m), respectively, along with excellent durability. The findings propose a novel strategy for modulating the electronic structure of metallic SAs catalysts and enhancing their stability through strong interactions between SAs and HEACs. [ABSTRACT FROM AUTHOR]

Improving the atomic utilization of storage sites and developing isotropic transport characteristics become crucial to enhance the performance of potassium‐ion hybrid capacitors (PIHCs), and the disordered strategy and coordination modulation of the electrodes can satisfy the above structure‐activity requirements. Herein, the highly dispersed atomic W‐P clusters are chosen as a platform for the electronic restructuring. Studies and calculations indicate that replacing O in W‐O2/P2 with pyridine N can modulate the electron distribution and electronegativity, and enrich the edge‐dangling bonds of the amorphous clusters (W‐N2/P2), resulting in proper adsorption equilibrium and high affinity for K+ storage. In addition, the clusters have isotropic and bulk‐phase‐indifferent fast ion storage, and in situ protection of carbon nanosheets can provide stable support for ion storage and electron transfer in the clusters. As an anode, the composite (W‐N/P@C) exhibits superior storage properties of K+ (reversible capacity of 181.6 mAh g−1 after 3000 cycles at 5.0 A g−1), with high energy density (163.7 Wh Kg−1) at the high‐power output (3500 W Kg−1) in PIHCs. This work systematically delineates the effects of disordered design and pyridine N‐coordination on energy storage, and provides new research ideas for studying high‐performance PIHCs. [ABSTRACT FROM AUTHOR]

By using bimetallic complexe to construct adjacent structure of atomic clusters and single atoms, which performs well in ORR and Zn-air batteries. [Display omitted] Electrocatalysts are useful in lowering the energy barrier in oxygen reduction reaction (ORR). In this study, a catalyst with neighboring Fe single-atom and cluster is created by adsorbing a bimetallic Fe complex onto N -doped carbon and then pyrolyzing it. The resulting catalyst has good performance and a half-wave potential of 0.89 V. When used in Zn-air batteries, the voltage drops by only 8.13 % after 145 h of cycling. Theoretical studies show that electrons transfer from neighboring clusters to single atoms and the catalyst has a lower d-band center. These reduce intermediate desorption energy, hence improving ORR performance. This work demonstrates the capacity to adjust the catalytic properties through the interaction of diverse metal structures, which helps to design more efficient catalysts. [ABSTRACT FROM AUTHOR]

Electrochemical activation usually accompanies in situ atom rearrangement forming new catalytic sites with higher activity due to reconstructed atomic clusters or amorphous phases with abundant dangling bonds, vacancies, and defects. By harnessing the pre‐catalytic process of reconstruction, a multilevel structure of CuNi alloy nanoparticles encapsulated in N‐doped carbon (CuNi nanoalloy@N/C) transforms into a highly active compound of Ni‐doped CuO nanocluster supported on (N/O‐C) co‐doped C. Both the exposure of accessible active sites and the activity of individual active sites are greatly improved after the pre‐catalytic reconstruction. Manipulating the Cu/Ni ratios of CuNi nanoalloy@N/C can tailor the electronic property and d‐band center of the high‐active compound, which greatly optimizes the energetics of oxygen evolution reaction (OER) intermediates. This interplay among Cu, Ni, C, N, and O modifies the interface, triggers the active sites, and regulates the work functions, thereby realizing a synergistic boost in OER. [ABSTRACT FROM AUTHOR]

This paper (i) explores the internal structure of two quantum mechanics datasets (QM7b, QM9), composed of several thousands of organic molecules and described in terms of electronic properties, and (ii) further explores an inverse design approach to molecular design consisting of using machine learning methods to approximate the atomic composition of molecules, using QM9 data. Understanding the structure and characteristics of this kind of data is important when predicting the atomic composition from physical‐chemical properties in inverse molecular designs. Intrinsic dimension analysis, clustering, and outlier detection methods were used in the study. They revealed that for both datasets the intrinsic dimensionality is several times smaller than the descriptive dimensions. The QM7b data is composed of well‐defined clusters related to atomic composition. The QM9 data consists of an outer region predominantly composed of outliers, and an inner, core region that concentrates clustered inliner objects. A significant relationship exists between the number of atoms in the molecule and its outlier/inliner nature. The spatial structure exhibits a relationship with molecular weight. Despite the structural differences between the two datasets, the predictability of variables of interest for inverse molecular design is high. This is exemplified by models estimating the number of atoms of the molecule from both the original properties and from lower dimensional embedding spaces. In the generative approach the input is given by a set of desired properties of the molecule and the output is an approximation of the atomic composition in terms of its constituent chemical elements. This could serve as the starting region for further search in the huge space determined by the set of possible chemical compounds. The quantum mechanic's dataset QM9 is used in the study, composed of 133,885 small organic molecules and 19 electronic properties. Different multi‐target regression approaches were considered for predicting the atomic composition from the properties, including feature engineering techniques in an auto‐machine learning framework. High‐quality models were found that predict the atomic composition of the molecules from their electronic properties, as well as from a subset of only 52.6% size. Feature selection worked better than feature generation. The results validate the generative approach to inverse molecular design. [ABSTRACT FROM AUTHOR]

Tensile tests were performed on Cu64Zr36 metallic glass at strain rates of 107/s, 108/s, and 109/s via classical molecular dynamics simulations to explore the underlying mechanism by which strain rate affects deformation behavior. It was found that strain rate has a great impact on the deformation behavior of metallic glass. The higher the strain rate is, the larger the yield strength. We also found that the strain rate changes the atomic structure evolution during deformation, but that the difference in the atomic structure evolution induced by different strain rates is not significant. However, the mechanical response under deformation conditions is found to be significantly different with the change in strain rate. The average von Mises strain of a system in the case of 107/s is much larger than that of 109/s. In contrast, more atoms tend to participate in deformation with increasing strain rate, indicating that the strain localization degree is more significant in cases of lower strain rates. Therefore, increasing the strain rate reduces the degree of deformation heterogeneity, leading to an increase in yield strength. Further analysis shows that the structural features of atomic clusters faded out during deformation as the strain rate increased, benefiting more homogeneous deformation behavior. Our findings provide more useful insights into the deformation mechanisms of metallic glass. [ABSTRACT FROM AUTHOR]

In this work, the geometric and electronic parameters of pure and vanadium-substituted anions of Lindqvist polyoxometalates have been investigated using DFT calculations. Active sites of all anions are identified through results on local and global reactivity descriptors. The results indicate that bridging oxygen atoms in all clusters are the most active sites. Using this, the mechanism of the catalytic generation of the hydroxyl radical from water was studied for the di-substituted Lindqvist polyoxometalate [V2Mo4O19]4−. This study provides a detailed understanding of this important intermediate step in photo-oxidation reactions. The mechanistic route makes it possible to locate transition states and intermediates structures and demonstrates that the pre-association of the water molecule leads to an H abstraction with an energy barrier of 26.42 kcal/mol and OH radical and [HV2Mo4O19]4− as products in this step. [ABSTRACT FROM AUTHOR]

Based on extensive global minimum searches augmented with first-principles theory calculations, we predict herein the first boron-based perfect tetrahedral clusters Td B16P4 (2) and Td B16As4 (3) which, as aromatic non-metal analogs of the experimentally observed Td Au20 (2003, Science299, 864), all contain a truncated Td B16 (1) cage at the center effectively stabilized by four trivalent non-metal atoms (P, As) at the corners. Detailed natural bonding orbital (NBO) and adaptive natural density partitioning (AdNDP) bonding analyses indicate that the valences of all the trivalent component atoms in these tetrahedral clusters are fully satisfied, rendering spherical aromaticity and extra stability to the systems. The IR, Raman, and photoelectron spectra (PES) of the concerned species are theoretically simulated to facilitate their characterizations in future experiments. [ABSTRACT FROM AUTHOR]

Copper has been reclusive with regard to its plasmonic investigations among the founding plasmonic metals. With the advent of technology and the associated improvements in understanding of plasmonics, copper has been able to make a stand for itself among its peers and even outshine them in a few aspects such as dielectric loss, cost, and a more intricate and facile tuning of the near and far field intensities of the plasmon-enhanced distributions. This review is aimed at highlighting the different classes of plasmonic copper (PC), ranging from its pristine version to the array of composited and alloyed compositions. The focus is on an all-encompassing review of PC with regard to its shortcomings and merits, its exploration for plasmonic applications, and emerging phenomena discovered due to the plasmonic virtue. We aim to bring about a comprehensive treatise of the investigations on PC, where the major discussions are on the topics of a generic treatise on surface plasmons (both localized and propagating), pristine copper and its potential for different applications, the almost inescapable phenomenon of oxidation, and the associations that copper has been made to form in order to be exploited for multiple uses such as chalcogenides, silicides, alloys, and other metamaterial architectures. Specific outcomes of the changes to the near and far-field distributions of PC in various conditions such as oxidized/alloyed/composited and stabilized have been discussed, highlighting the changes to PC in lieu of these modifications. The concluding sections highlight some fascinating compositions including multi-elemental copper and its atomic clusters and cursorily studied compositions which are among the few materials that could offer untapped capabilities which will be made evident from brief glimpses of their plasmonic character. The outlook for plasmonic copper has never been more promising, ranging from the need for comprehensive investigations of emerging material compositions and configurations (of both pristine and composited copper) to the realm of commercialization. Copper has, thus, been projected to be a viable alternative to existing options including the poster children of plasmonics, namely, silver and gold. [ABSTRACT FROM AUTHOR]

To delve into the microscopic property variations of the ConMoP(n = 1 ~ 5) cluster, this study employs density functional theory at the B3LYP/def2‐TZVP quantum chemistry level. The paper conducts a comprehensive theoretical analysis of the clusters, examining parameters such as bond lengths, bond angles, electronic localization function (ELF), interaction region indicator function (IRI), independent gradient model based on the Hirshfeld partition, deformation density, electronic space range, chemical hardness and softness, polarizability, and dipole moment. The optimization process reveals 16 stable configurations for the ConMoP(n = 1 ~ 5) cluster, predominantly taking on a steric form. As the cluster size increases, the electronic delocalization of Co atoms intensifies, while the electronic properties of Mo atoms remain relatively stable. Notably, P atoms maintain a high degree of electronic delocalization. The interatomic forces within the clusters predominantly exhibit covalent bonding, with no evident repulsive effects observed between atoms. The bonding between metal atoms in the clusters leans toward a preference for covalent interaction. The degree of dispersion in the clusters increases with their growth, particularly evident in configuration 5‐a, which displays a broader spatial distribution. Configuration 3‐a demonstrates the most favorable activity, showcasing a relatively stable structure. Overall, configuration 3‐a emerges as a focal point for catalytic reactions. This article provides a more comprehensive analysis of the ConMoP(n = 1 ~ 5) cluster, yielding diverse results and enhancing the theoretical understanding of this cluster. [ABSTRACT FROM AUTHOR]

To efficiently desorb H2, pure Mgn (n = 4–8) clusters were chosen for the hydrogen evolution reaction with H2O. At the PBE0/def2‐TZVP level and the PBE0‐D3/def2‐TZVP level, the lowest energy structures of Mgn (n = 4–8) clusters and the most stable structures of Mgn@H2O (n = 4–8) complexes were searched in the local region. The transition state was predicted, and then the hydrogen evolution reaction channel was obtained by using the intrinsic reaction coordinate (IRC) to confirm the transition state. To better analyze the hydrogen reaction mechanism, the character of Mgn@H2O (n = 4–8) complexes and MgnO (n = 4–8) clusters, as well as the atomic charge change trend, were investigated using interaction region indicator function analysis (IRI) and natural population analysis (NPA). The reaction effect of Mg4 cluster and H2O is the worst. The energy barrier does, however, progressively lower as the cluster atom count rises, improving the reaction effect. [ABSTRACT FROM AUTHOR]

A molecular dynamics-based model of semi-solid formation from liquid melt of the novel Al–15Mg2Si–4.5Si composite is reported in the present study. Growth kinetics of Mg2Si phase is studied here at the pre-nucleation stage i.e., prior to the emergence of a stable nucleus. Moreover, insight has been grabbed on semi-solid processing of the said composite at atomic level, wherein the dynamic evolution of the Mg–Si clusters has been studied during cooling/semi solid slurry generation as well as during isothermal holding stage. The effect of variation of cooling rate on the number of clusters, average size of clusters and density of clusters has been investigated. The average size of clusters decays exponentially with cooling rate, whereas the average atomic density of clusters decays following a power-law relation with cooling rate. The change of the thermodynamic parameters (enthalpy and potential energy) during the phase transformation from liquid to semi-solid state are determined here, which are then employed to determine the value of interfacial free energy of Mg2Si-melt interface in the Al–15Mg2Si–4.5Si composite, along with the parameters obtained from the dynamic evolution of Mg-Si clusters. The paper also reports the temporal evolution of solid content within the melt, corresponding to the Mg2Si phase, during slurry generation as well as during isothermal holding stage. [ABSTRACT FROM AUTHOR]

Different transition metal loaded metal–organic frameworks (MOFs) have been extensively studied. However, little literature has been written about alkali and alkali-earth metal-loaded MOFs. In this study, we take the DPyDFP linker used for the construction of MOFs as an example. The structures and electronic properties of alkali metals and alkaline earth metals loaded DPyDFP clusters have been investigated using density functional theory. The results indicate that the structural stability of alkali metals and alkaline earth metals loaded DPyDFP clusters is less than that of transition metals loaded DPyDFP clusters. The interior of the DPyDFP clusters has not enough space to locate a large alkali metal or alkaline earth metal atom except for Li, Be and Mg. It indicates that if the IAM and IIAM atoms are loaded on the linker to build a MOF framework, Li, Be and Mg are worth considering. The DPyDFP-IIAM clusters exhibit more structural stability and chemically stable than corresponding DPyDFP-IAM clusters. The HOMOs and LUMOs of the DPyDFP-IAM and DPyDFP-IIAM clusters mostly surround N and C atoms. The IAM-N and IIAM-N bonds exhibit certain covalent character. Due to the limited charge transfer between the IAM (or IIAM) atoms and the DPyDFP clusters, the IAM (or IIAM) atoms are not a good choice to design the novel linker to build a MOF framework. [ABSTRACT FROM AUTHOR]

Context: Hydrogen has emerged as a promising clean energy carrier, underscoring the imperative need to comprehend its adsorption mechanisms. This study delves into the magnetic and electronic properties of Co-Mo-P clusters, aiming to unveil their catalytic potential in hydrogen production. Employing density functional theory (DFT), we optimized cluster configurations and scrutinized their magnetic behaviors. Our investigation unveiled 16 stable configurations of the ConMoP (n = 1 ~ 5) cluster, predominantly in steric forms. The magnetic attributes were primarily ascribed to the d orbitals of Co metal atoms, with Co3MoP exhibiting exceptional magnetic characteristics. Analysis of density of state diagrams revealed the prevalence of spin-up α-electrons in d orbitals, while spin-down β-electrons attenuated overall magnetic properties. Localized orbital (LOL) analysis highlighted stable covalent bonds within the clusters, affirming their catalytic potential. Orbital delocalization index (ODI) analysis revealed diverse spatial distribution ranges for orbitals across different configurations, suggesting a progressive attenuation of off-domain properties with increasing cluster size. Furthermore, infrared spectroscopy unveiled distinct vibrational peaks in various configurations, indicative of unique infrared activities. These findings contribute to a nuanced theoretical understanding of Co-Mo-P clusters and pave the path for future research aimed at augmenting their catalytic efficiency in hydrogen production. This study underscores the viability of Co-Mo-P clusters as alternatives to conventional Pt catalysts, offering insights into the design of novel materials for sustainable energy applications. Further research is warranted to explore the behavior of the Co-Mo-P system under diverse reaction conditions, fostering advancements in materials and energy science. Methods: In this study, we harnessed the ConMoP (n = 1 ~ 5) cluster as a simulation platform for probing the local structure of the material. Our aim was to scrutinize the magnetism, electronic characteristics influenced by the varying metal atoms within these clusters. A systematic exploration involved incrementing the number of metal atoms and expanding the cluster size to elucidate the corresponding property variations. Density functional theory (DFT) calculations were pivotal to our methodology, employing the B3LYP hybrid functional implemented in the Gaussian 16 software package. The ConMoP (n = 1 ~ 5) cluster underwent optimization calculations and vibrational analysis at the def2-tzvp quantization level, yielding optimized configurations with diverse spin multiplet degrees. To comprehensively characterize and visually represent the stability, electronic features, and catalytic attributes of these configurations, we employed a suite of computational tools. Specifically, quantum chemistry software GaussView and wave function analysis software Multiwfn played integral roles. Through the integrated use of these computational tools, we acquired valuable insights into the magnetism, electronic characteristics of the ConMoP (n = 1 ~ 5) cluster, shedding light on their dependency on distinct metal atoms. [ABSTRACT FROM AUTHOR]

Spectra of rare gas atom clusters containing a single carbon dioxide molecule are observed using a tunable mid-infrared (4.3 µm) source to probe a pulsed slit jet supersonic expansion. There are relatively few previous detailed experimental results on such clusters. The assigned clusters include CO2–Arn with n = 3, 4, 6, 9, 10, 11, 12, 15, and 17, and CO2–Krn and CO2–Xen with n = 3, 4, and 5. Each spectrum has (at least) a partially resolved rotational structure, and each yields precise values for the shift of the CO2 vibrational frequency (ν3) induced by the nearby rare gas atoms, together with one or more rotational constants. These results are compared with theoretical predictions. The more readily assigned CO2–Arn species tend to be those with symmetric structures, and CO2–Ar17 represents completion of a highly symmetric (D5h) solvation shell. Those not assigned (e.g., n = 7 and 13) are probably also present in the observed spectra but with band structures that are not well-resolved and, thus, are not recognizable. The spectra of CO2–Ar9, CO2–Ar15, and CO2–Ar17 suggest the presence of sequences involving very low frequency (≈2 cm−1) cluster vibrational modes, an interpretation which should be amenable to theoretical confirmation (or rejection). [ABSTRACT FROM AUTHOR]

We developed a method for evaluating the accuracies of the local properties of DFT functionals in detail using a clustering method based on machine learning and structural/electronic descriptors. We generated 36 clusters consistent with human intuition using 30,436 carbon atoms from the QM9 dataset. The results were used to evaluate 13C NMR chemical shifts calculated using 84 DFT functionals. Carbon atoms were grouped based on their similar environments, reducing errors within these groups. This enables more accurate assessment of the accuracy using a specific DFT functional. Therefore, the present atomic clustering provides more detailed insight into accuracy verification. [ABSTRACT FROM AUTHOR]

Due to the transient interaction between laser and powder and layer-by-layer rapid melting and solidification, laser additive manufacturing-fabricated metal components can exhibit unique microstructure evolution behaviors and strengthening mechanisms that are normally not available in traditional processes. In this work, a previously unreported rapid hardening behavior at the very early stage of isothermal aging for laser powder bed fusion-processed high-strength Al-5024 alloy was revealed. The microstructures and mechanical properties of specimens aged from 10 min to 120h were systematically analyzed. It showed that the specimens underwent two peak hardening processes during an isothermal aging at 325 °C. The mechanical properties of the specimens including microhardness, yield strength, and elastic modulus were significantly enhanced after an extremely short aging time of 10 min and then reached a secondary peak hardening at an aging time of 4h, where the yield strength of 450 ± 10.3 and 463.2 ± 13.2 MPa were obtained, respectively. The unusual aging responses were attributed to the formation and decomposition of Sc-rich clusters with a high number density of 2.7 × 1023 m−3 and nano-size of 2.71 nm. These clusters were characterized by transmission electron microscopy analyses and further supported by differential scanning calorimetry measurements, where a significantly higher activation energy of 147.6 ± 21.1 kJ/mol corresponding to the precipitation/coarsening process of Al3(Sc,Zr) was measured for rapid hardening specimens. In addition, the relationship between the aging process, the evolution of nano-precipitates, and the mechanical properties was systematically demonstrated. [ABSTRACT FROM AUTHOR]

Single atom alloy AgCu catalysts have attracted great attention, since doping the single Cu atom introduces narrow free-atom-like Cu 3d states in the electronic structure. These peculiar electronic states can reduce the activation energies in some reactions and offer valuable guidelines for improving catalytic performance. However, the geometric tuning effect of single Cu atoms in Ag catalysts and the structure–activity relationship of AgCu catalysts remain unclear. Here, we prepared well-resolved pristine Agn− as well as single atom alloy Agn−1Cu− and Agn−1Au− (n = 7–20) clusters and investigated their reactivity with O2. We found that replacing an Ag atom in Agn− (n = 15–18) with a Cu atom significantly increases the reactivity with O2, while replacement of an Ag with an Au atom has negligible effects. The adsorption of O2 on Agn− or Agn−1Cu− clusters follows the single electron transfer mechanism, in which the cluster activity is dependent on two descriptors, the energy level of α-HOMO (strong correlation) and the α-HOMO–LUMO gap (weak correlation). Our calculation demonstrated that the cluster arrangements caused by single Cu atom alloying would affect the above activity descriptors and, therefore, regulates clusters' chemical activity. In addition, the observed reactivity of clusters in the representative sizes with n = 17–19 can also be interpreted using the symmetry-adapted orbital model. Our work provides meaningful information to understand the chemical activities of related single-atom-alloy catalysts. [ABSTRACT FROM AUTHOR]

One or two phenylacetylide (PA) ligand(s) were successfully removed from the IrAu12 superatomic core of [IrAu12(dppe)5(PA)2]+ (dppe=1,2‐bis(diphenylphosphino)ethane) by reaction with controlled amounts of tetrafluoroboric acid. Optical and nuclear magnetic resonance spectroscopies and density functional theory calculations revealed the formation of open Au site(s) on the IrAu12 core of [IrAu12(dppe)5(PA)1]2+ and [IrAu12(dppe)5]3+ with the remaining structure intact. Isocyanide was efficiently trapped at the open electrophilic site on [IrAu12(dppe)5(PA)1]2+, whereas a dimer or trimer of the IrAu12 superatoms was formed using diisocyanide as a linker. These results open the door to designed assembly of chemically modified metal superatoms. [ABSTRACT FROM AUTHOR]

One or two phenylacetylide (PA) ligand(s) were successfully removed from the IrAu12 superatomic core of [IrAu12(dppe)5(PA)2]+ (dppe=1,2‐bis(diphenylphosphino)ethane) by reaction with controlled amounts of tetrafluoroboric acid. Optical and nuclear magnetic resonance spectroscopies and density functional theory calculations revealed the formation of open Au site(s) on the IrAu12 core of [IrAu12(dppe)5(PA)1]2+ and [IrAu12(dppe)5]3+ with the remaining structure intact. Isocyanide was efficiently trapped at the open electrophilic site on [IrAu12(dppe)5(PA)1]2+, whereas a dimer or trimer of the IrAu12 superatoms was formed using diisocyanide as a linker. These results open the door to designed assembly of chemically modified metal superatoms. [ABSTRACT FROM AUTHOR]

Luminescence is observed in three novel macropolyhedral nineteen‐ and eighteen‐vertex chalcogenaboranes: Se2B17H17 (1), SeB17H19 (3) and SeB18H20 (4). This led us to the recognition that previously published macropolyhedral heteroborane species might also exhibit luminescence. Thus, the known nineteen‐ and eighteen‐vertex dithiaboranes S2B17H17 (2), n‐S2B16H16 (5) and i‐S2B16H16 (6) were synthesised and also found to exhibit a range of luminescent properties. These macropolyhedral species are very different from the previously unique fluorescent binary borane B18H22 in terms of their structural architectures, by the presence of borane cluster hetero atoms, and, as in the cases of 5 and 6, that their synthetic origins are not derived simply through the modification of B18H22 itself. They consequently greatly expand the possibilities of finding new luminescent inorganic borane species. [ABSTRACT FROM AUTHOR]

Luminescence is observed in three novel macropolyhedral nineteen‐ and eighteen‐vertex chalcogenaboranes: Se2B17H17 (1), SeB17H19 (3) and SeB18H20 (4). This led us to the recognition that previously published macropolyhedral heteroborane species might also exhibit luminescence. Thus, the known nineteen‐ and eighteen‐vertex dithiaboranes S2B17H17 (2), n‐S2B16H16 (5) and i‐S2B16H16 (6) were synthesised and also found to exhibit a range of luminescent properties. These macropolyhedral species are very different from the previously unique fluorescent binary borane B18H22 in terms of their structural architectures, by the presence of borane cluster hetero atoms, and, as in the cases of 5 and 6, that their synthetic origins are not derived simply through the modification of B18H22 itself. They consequently greatly expand the possibilities of finding new luminescent inorganic borane species. [ABSTRACT FROM AUTHOR]

Constructing Sb atomic clusters with obvious size effect in Sb/C composites has great potential for boosting electrochemical reactivity toward ultrahigh rate and long‐term sodium storage. However, how to balance the contradiction between ultra‐small size of Sb atomic clusters and high loading in a specific Sb/C composite is an unprecedented challenge. Here, a facile in situ vaporization‐reduction strategy is presented for preparing Sb atomic clusters@N, S co‐doped carbon networks (Sb ACs@NSC). Featuring the high content of Sb atomic clusters (45.30 wt%, ICP) with superior electrochemical activity, robust Sb─O─C bond and N, S co‐doped conductive carbon matrix, the Sb ACs@NSC electrode possessed ultrafast electrochemical kinetics and impressive long‐term cycling stability for providing unprecedented rate capability of 245.7 mAh g−1 at ultrahigh rate of 80 A g−1 and maintaining highlighted capacity of 306.7 mAh g−1 after 1000 cycles under 10 A g−1, outperforming all reported Sb‐based materials for SIBs. The DFT calculations further revealed that the Sb─O─C bond and N, S co‐doped carbon matrix are beneficial for stable adsorption capabilities and fast electrochemical kinetics of Na+. The designing compromised dense Sb atomic clusters and powerful interface bond will light on developing advanced atomic materials for energy storage and conversion. [ABSTRACT FROM AUTHOR]

A systematic electronic structure analysis was conducted for M(L)n molecular electrides and their corresponding alkalide units M(L)n@M' (M/M' = Na, K; L = Tren, Azacryptand, TriPip222; n = 1, 2). All complexes belong to the "superalkali" category due to their low ionization potentials. The saturated molecular electrides display M+(L)n- form with a greatly diffuse quasispherical electron cloud. They were identified as "superatoms" considering the contours of populating atomic-type molecular orbitals. The observed superatomic Aufbau order of M(Tren)2 is 1S, 1P, 1D, 1F, 2S, 2P, and 1G and it is consistent with those of M(Azacryptand) and M(TriPip222) up to the analyzed 1F level. Their excitation energies decrease gradually moving from M(Tren)2 to M(Azacryptand) and to M(TriPip222). The studied alkalide complexes carry [M(L)n]+@M'- ionic structure and their dissociation energies vary in the sequence of K(L)n@Na > Na(L)n@Na > K(L)n@K > Na(L)n@K. Similar to molecular electrides, the anions of alkalide units occupy electrons in diffuse Rydberg-like orbitals. In this work, excited states of [M(L)n@M']0/+/- and their trends are also analyzed. [ABSTRACT FROM AUTHOR]

Hydrogen evolution reaction (HER) is a promising route for sustainable hydrogen production. However, its efficiency is limited by kinetic barriers. Herein, we employ density functional theory (DFT) calculations to demonstrate a new strategy of embedding tetrametallic transition metal clusters (3TM 1 -TM 2) into the pores of graphdiyne (GDY) to effectively optimize its HER performance. By screening 900 configurations, 10 prototypes displayed near-ideal hydrogen adsorption free energies. Among them, 3W–Hg@GDY with a ΔG H of −0.00035 eV was identified as the optimal candidate. Analysis of the electronic structure reveals hybridization between the metal d orbitals and GDY p orbitals near the Fermi level, creating partially filled impurity states to promote hydrogen adsorption. Additionally, coordination between the three TM 1 atoms and active TM 2 atom in the cluster enables precise tuning of TM 2 's electron density to achieve a moderate interaction with the adsorbed H, facilitating superior HER catalysis. Our findings showcase a new paradigm of cluster engineering for modulating GDY's reactivity that holds great promise as a universal approach for the design of high-performance GDY-based electrocatalysts beyond HER. Through screening 900 configurations of tetrametallic transition metal clusters embedded in graphdiyne via DFT calculations, we identified 10 prototypes displayed near-ideal hydrogen adsorption free energies. [Display omitted] • Screened 900 GDY-cluster configs; 10 show near-ideal HER adsorption energies. • 3 W–Hg@GDY: ΔG H -0.00035 eV, closest to ideal among prototypes. • Metal d-orbitals, GDY p-orbitals hybridization aids H adsorption. • Precisely tuned electron density on active site via coordination with three atoms enables optimal binding. [ABSTRACT FROM AUTHOR]

In this work, density-functional theory (DFT) was used to investigate the geometry and electronic structure of Run(n = 1–6,10) supported on CeO2(110) (Run(n = 1–6,10)/CeO2(110)) and their electrocatalytic properties for the N2 reduction reaction (NRR). The results indicated that there is a strong metal–support interaction between Run and CeO2(110), which leads to large surface distortion and stabilized Run. On Run(n = 1–6,10)/CeO2(110), N2 captured in the end-on mode is thermodynamically more favorable than that captured in the side-on mode; however, the side-on mode can lead to stronger activation of N2 which promotes the following protonation step of N2. For Run(n = 3,5,6)/CeO2(110), the electrochemical NRR prefers to occur via an enzymatic mechanism with limiting potentials of −0.31, −0.53 and −0.66 V. The electrocatalytic activity of Run(n = 1–6,10)/CeO2(110) for the NRR shows a strong size dependence. For Ru3/CeO2(110), it has the lowest absolute value of limiting potential, and with the increase in n (n > 3), the limiting potential becomes more negative. Moreover, Ru3/CeO2(110) shows high selectivity and stability. This study gives valuable insights for designing effective catalysts for the NRR. [ABSTRACT FROM AUTHOR]

Superatoms are promising as new building block materials that can be designed by precise controlling of the constituent atoms. Stannaspherene (Sn122−) is a rigid cage‐like cluster with icosahedral symmetry, for which one‐atom encapsulation was theoretically expected and detected in the gas phase. Here, a single‐atom introduction method into stannaspherene using a dendrimer template with polyvinylpyrrolidone (PVP) protection is demonstrated. This advanced solution‐phase synthesis allows not only the selective doping of one atom into the cluster cage, but also enable further detail characterization of optical and magnetic properties that were not possible in the gas‐phase synthesis. In other words, this liquid‐phase synthesis method has enabled the adaptation of detailed analytical methods. In this study, FeSn12 was synthesized and characterized, revealing that a single Fe atom introduction in the Sn122− cage result in the appearance of near‐infrared emission and enhancement in the magnetism. [ABSTRACT FROM AUTHOR]

Metal individual atoms and few-atom clusters show extraordinary catalytic properties for a variety of organic reactions, however, their implementation in total synthesis of complex organic molecules is still to be determined. Here we show a 11-step linear synthesis of the natural product (±)-Licarin B, where individual Pd atoms (Pd1) catalyze the direct aerobic oxidation of an alcohol to the carboxylic acid (steps 1 and 6), Cu2-7 clusters catalyze carbon-oxygen cross couplings (steps 3 and 8), Pd3-4 clusters catalyze a Sonogashira coupling (step 4) and Pt3-5 clusters catalyze a Markovnikov hydrosylilation of alkynes (step 5), as key reactions during the synthetic route. In addition, the new synthesis of Licarin B showcases an unexpected selective alkene hydrogenation with metal-free NaBH4 and an acid-catalyzed intermolecular carbonyl-olefin metathesis as the last step, to forge a trans-alkene group. These results, together, open new avenues in the use of metal individual atoms and clusters in organic synthesis, and confirm their exceptional catalytic activity in late stages during complex synthetic programmes. Individual metal atoms and few-atom metal clusters have shown promising catalytic activities, however, their exploitation in the total synthesis of complex organic molecules remains underexplored. Here, the authors develop a total synthesis of the bioactive natural product (±)-Licarin B involving key steps catalyzed by soluble individual Pd atoms and Cu/Pd/Pt clusters, achieving an 11-step linear synthesis and overall yield of 13.1%. [ABSTRACT FROM AUTHOR]

Metal individual atoms and few-atom clusters show extraordinary catalytic properties for a variety of organic reactions, however, their implementation in total synthesis of complex organic molecules is still to be determined. Here we show a 11-step linear synthesis of the natural product (±)-Licarin B, where individual Pd atoms (Pd1) catalyze the direct aerobic oxidation of an alcohol to the carboxylic acid (steps 1 and 6), Cu2-7 clusters catalyze carbon-oxygen cross couplings (steps 3 and 8), Pd3-4 clusters catalyze a Sonogashira coupling (step 4) and Pt3-5 clusters catalyze a Markovnikov hydrosylilation of alkynes (step 5), as key reactions during the synthetic route. In addition, the new synthesis of Licarin B showcases an unexpected selective alkene hydrogenation with metal-free NaBH4 and an acid-catalyzed intermolecular carbonyl-olefin metathesis as the last step, to forge a trans-alkene group. These results, together, open new avenues in the use of metal individual atoms and clusters in organic synthesis, and confirm their exceptional catalytic activity in late stages during complex synthetic programmes. Individual metal atoms and few-atom metal clusters have shown promising catalytic activities, however, their exploitation in the total synthesis of complex organic molecules remains underexplored. Here, the authors develop a total synthesis of the bioactive natural product (±)-Licarin B involving key steps catalyzed by soluble individual Pd atoms and Cu/Pd/Pt clusters, achieving an 11-step linear synthesis and overall yield of 13.1%. [ABSTRACT FROM AUTHOR]

Fe─N─C materials with Fe─N4 sites are considered as most promising non‐precious metal‐based electrocatalysts for low‐cost proton‐exchange‐membrane fuel cells (PEMFCs). Breaking the trade‐off between activity and stability has been a long‐standing challenge in the field of acidic oxygen reduction reaction (ORR). Herein, a "top‐down" thermally‐driven strategy is developed to achieve highly active pyrrolic N‐coordinated Fe sites in a high spin state with Fe atomic cluster (Fen@Fe─Npyrr─C) and discover that the neighboring Fen cluster can synergistically stabilize such vulnerable Fe─N4 sites by inhibiting their protonation. Consequently, the Fen@Fe─Npyrr─C catalysts exhibit much enhanced ORR activity and stability, endowing PEMFCs with a high power density of 804.6 mW cm−2 (testing conditions: 80 °C, 100% RH, 2.0 bar) and over 100 h durability (at 0.5 V). These findings open up opportunities for the exploration of durable Fe─N─C ORR electrocatalysts for non‐precious metal‐based PEMFCs and other applications. [ABSTRACT FROM AUTHOR]

The synthesis and structural characterization of the first sulfur-containing derivatives of the C,C-biscarborane {ortho-C2B10}2 cluster – thiol, thioether, and disulfide – are reported. The biscarboranyl dithiol (1-HS-C2B10H10)2 exhibits an exceedingly long intracluster carbon–carbon bond length of 1.858(3) Å, which is attributed to the extensive interaction between the lone pairs of the thiol groups and the unoccupied molecular orbital of the carborane cluster. The structures of the doubly deprotonated biscarboranyl dithiolate anion (1-S-C2B10H10)22− with various counter cations feature an even longer carbon–carbon bond length of 2.062(10) Å within the cluster along with a short carbon–sulfur bond of 1.660(7) Å, both indicative of significant delocalization of electron density from the sulfur atoms into the cluster. [ABSTRACT FROM AUTHOR]

Giant heterometallic polyoxometalate (POM) clusters with precise atom structures, flexibly adjustable and abundant active sites are promising for constructing functional nanodrugs. However, current POM drugs are almost vacant in orthotopic brain tumor therapy due to the inability to effectively penetrate the blood–brain barrier (BBB) and low drug activity. Here, we designed the largest (3.0 nm × 6.0 nm) transition‐metal–lanthanide co‐encapsulated POM cluster {[Ce10Ag6(DMEA)(H2O)27W22O70][B‐α‐TeW9O33]9}288− featuring 238 metal centers via synergistic coordination between two geometry‐unrestricted Ce3+ and Ag+ linkers with tungsten‐oxo cluster fragments. This POM was combined with brain‐targeted peptide to prepare a brain‐targeted nanodrug that could efficiently traverse BBB and target glioma cells. The Ag+ active centers in the nanodrug specifically activate reactive oxygen species to regulate the apoptosis pathway of glioma cells with a low half‐maximal inhibitory concentration (5.66 μM). As the first brain‐targeted POM drug, it efficiently prolongs the survival of orthotopic glioma‐bearing mice. [ABSTRACT FROM AUTHOR]

Developing atomically dispersed metal on nitrogen‐doped carbon (M─N─C) catalyst provides a promising strategy to convert CO2 into high‐valued chemicals and achieve artificially closed carbon cycles. However, it is challenging to tune the structure and coordination of N─M bond that further improve the intrinsic activity and selectivity of CO2RR. Herein, CuNi atomic clusters embedded in Ni/Cu dual atomic sites catalysts (CuNiAC@Ni/Cu─N─C) are designed and successfully manipulated to regulate the coordination environment for M─N─C catalysts to enhance the CO2 electroreduction reaction (CO2RR). The most active configuration in CuNiAC@Ni/Cu─N─C catalyst is CuNi atomic cluster connected with 2N‐bridged (Ni‐Cu)N5, in which two N atoms are shared with NiN4 and CuN3 moieties verified by both systematic advanced characterizations and density function theory (DFT) calculations. The results have revealed the integration between CuNi atomic cluster and N4Ni/CuN3 dual‐metal atomic sites that optimize the electronic redistribution and narrow the bandgap, thereby decreasing the energy barrier of the potential determination step and promoting CO production. [ABSTRACT FROM AUTHOR]

Giant heterometallic polyoxometalate (POM) clusters with precise atom structures, flexibly adjustable and abundant active sites are promising for constructing functional nanodrugs. However, current POM drugs are almost vacant in orthotopic brain tumor therapy due to the inability to effectively penetrate the blood–brain barrier (BBB) and low drug activity. Here, we designed the largest (3.0 nm × 6.0 nm) transition‐metal–lanthanide co‐encapsulated POM cluster {[Ce10Ag6(DMEA)(H2O)27W22O70][B‐α‐TeW9O33]9}288− featuring 238 metal centers via synergistic coordination between two geometry‐unrestricted Ce3+ and Ag+ linkers with tungsten‐oxo cluster fragments. This POM was combined with brain‐targeted peptide to prepare a brain‐targeted nanodrug that could efficiently traverse BBB and target glioma cells. The Ag+ active centers in the nanodrug specifically activate reactive oxygen species to regulate the apoptosis pathway of glioma cells with a low half‐maximal inhibitory concentration (5.66 μM). As the first brain‐targeted POM drug, it efficiently prolongs the survival of orthotopic glioma‐bearing mice. [ABSTRACT FROM AUTHOR]

The advanced oxidation process based on peroxymonosulfate (PMS) is a new water purification strategy. In this work, Ni/Fe bimetallic atom cluster composite catalyst is prepared by a hydrothermal synthesis to stimulate PMS to produce high concentration singlet oxygen (1O2) and efficiently remove bisphenol A (BPA) from aqueous solution. The experimental data show that in a broad pH range (pH=3–11), the removal rate of BPA by the non‐free radical pathway induced by 1O2 is close to 100 %, and the catalyst still has high stability after 5 cycles. The mechanism of BPA removal in NiFe−BC/PMS/BPA catalytic degradation system is investigated by quenching experiment. It is found that 1O2 in the system is the most important active component in the degradation process of BPA, and a high concentration of 1O2 could promote the rapid degradation of BPA in solution. In this paper, the high catalytic activity and selectivity of bimetallic atomic cluster catalysts can provide new insights for the treatment of phenolic wastewater. [ABSTRACT FROM AUTHOR]

Silver and copper clusters capped by external chelating dithiolate ligands can be classified according to the cavities in their central coinage metal polyhedra. Silver clusters composed exclusively of fused tetrahedra are analogous to simple saturated organic compounds. The only interstitial atom that can be fit into an Ag4 tetrahedron is hydrogen. Silver polyhedra with larger trigonal prismatic or cubic cavities, including highly distorted cubic cavities, can accommodate halide and chalcogenide anions. The still larger 12-vertex icosahedral and cuboctahedral coinage metal cavities can accommodate oxoanions of the types SO32− and SO42− and their heavier congeners or alternatively interstitial coinage or platinum group metals leading to central M′@M12 units. Copper clusters with central cuboctahedra and silver clusters with central icosahedra possessing interstitial metal atoms approximate sphericality and provide examples of electron-rich metal superatoms with an average metal oxidation state of less than +1. Such copper cluster superatoms have two extra electrons corresponding to a filled 1S2 superatomic orbital. The silver cluster superatoms are electron richer with eight extra electrons corresponding to filled 1S2 + 1P6 superatomic orbitals. In these silver clusters seven or eight faces of the central Ag12 icosahedron are capped by additional silver atoms in order to provide these additional electrons. [ABSTRACT FROM AUTHOR]

The efficiency and performance of proton exchange membrane fuel cells (PEMFCs) are primarily influenced by ORR electrocatalysts. In recent years, atomically dispersed metal–nitrogen–carbon (M-N-C) catalysts have gained significant attention due to their high active center density, high atomic utilization, and high activity. These catalysts are now considered the preferred alternative to traditional noble metal electrocatalysts. The unique properties of M-N-C catalysts are anticipated to enhance the energy conversion efficiency and lower the manufacturing cost of the entire system, thereby facilitating the commercialization and widespread application of fuel cell technology. This article initially delves into the origin of performance and degradation mechanisms of Fe-N-C catalysts from both experimental and theoretical perspectives. Building on this foundation, the focus shifts to strategies aimed at enhancing the activity and durability of atomically dispersed Fe-N-C catalysts. These strategies encompass the use of bimetallic atoms, atomic clusters, heteroatoms (B, S, and P), and morphology regulation to optimize catalytic active sites. This article concludes by detailing the current challenges and future prospects of atomically dispersed Fe-N-C catalysts. [ABSTRACT FROM AUTHOR]

The transport properties of gold clusters with eight and nine atoms between gold electrodes are investigated by using non-equilibrium Green's function method combined with density functional theory. Negative differential resistance effect is found both in Au8 and Au9. From a new respect, the mechanism for the negative differential resistance effect is explored through calculating the number of electrons of the atoms in the clusters at different bias voltages. When Au9 takes vertical orientation, it is found that the voltage can change the coupling strength of the sandwiched system. When the value of the voltage is small, the current increases with decreasing of the cluster-electrode separation. But when the voltage increases to a certain value, the current decreases with decreasing of the cluster-electrode separation. When Au9 takes parallel orientation, different from other electronic transport systems, it is found that the transport behaviors for Au9 are not sensitive to the cluster-electrode separation, showing that this configuration has a better transport stability over the changes in distance, which may provide some new clues for developing future electron device. [ABSTRACT FROM AUTHOR]

The glass transformation processes of Ti75Al25, Ni50Zr50 and Cu50Zr50 were simulated by molecular dynamics method. The average atomic volume and radial pair distribution function were obtained. Besides, the number of icosahedral and icosahedral-like clusters were calculated by Voronoi polyhedron index analysis. Eventually, the dynamic evolution of amorphous atoms from short order to medium order and then to long range disorder was studied by analyzing the type and number of clusters during glass transformation. The results show that the glass forming ability is closely related to the type and number of Voronoi clusters. Besides, the clusters with high local quintuple symmetry tend to join together in order to form chains during the glass transformation process, which densely fills the whole space and reduces the dynamic behavior of the system. Furthermore, the plastic deformation tends to occur at the area with low local quintuple symmetry. It is intriguing to note that the abrupt changes of the types and number of clusters near the glass transformation temperature reflect the self-organized criticality behavior of metallic glass. [ABSTRACT FROM AUTHOR]

Copper homometallic and copper-rich heterometallic nanoclusters with some Cu(0) character are reviewed. Their structure and stability are discussed in terms of their number of "free" electrons. In many aspects, this structural chemistry differs from that of their silver or copper homologs. Whereas the two-electron species are by far the most numerous, only one eight-electron species is known, but more electron-rich nanoclusters have also been reported. Owing to the relatively recent development of this chemistry, it is likely that more electron-rich species will be reported in the future. [ABSTRACT FROM AUTHOR]

Highlights: arsenian pyrite and marcasite with pronounced chemical zoning are synthesized Au-As atomic clusters with probable composition of [AuAs10] form in pyrite incorporation of Au in As-rich pyrite proceeds via a reductive deposition mechanism in marcasite the Au and As concentrations are not correlated the "invisible" gold content in pyrite is dictated by the hydrothermal fluid chemistry Hydrothermal synthesis experiments were performed in order to quantify the states of Au and As in pyrite and marcasite. The experiments were performed at 350 °C/500 bar and 490 °C/1000 bar (pyrite–pyrrhotite buffer, C(NaCl) = 15 and 35 wt.%). The synthesis products were studied by EPMA, LA-ICP-MS, and EBSD. The EPMA was applied for simultaneous determinations of Au, As, Fe, and S, with a Au detection limit of 45–48 ppm (3σ). The analyses were performed along profiles across zonal grains. The concentrations of As and Au up to 5 wt.% and 8000 ppm, respectively, were determined in pyrite and up to 6 wt.% and 1300 ppm in marcasite. In pyrite, the Au concentration decreases with fluid salinity and temperature increases. Strong positive Au–As correlation and strong negative Au–Fe and As–S correlation were identified in pyrite. Comparison of the correlations with theoretical lines implies Au–As clustering. The cluster stoichiometry is inferred to be [AuAs10]. Most probably, As in pyrite presents in the form of clusters and in the As→S solid solution. Incorporation of Au in As-rich pyrite can be controlled by the reductive deposition mechanism. In marcasite, the concentrations of Au are not correlated with the As content. The [AuAs10] clusters enrich the {210}, {113}, and {111} pyrite faces, where the former exhibits the highest affinity to Au and As. The affinity of {110} and {100} forms to Au and As is lower. Implication of the experimental results to data for natural auriferous pyrite shows that the increase of Au content at C(As) > 0.5–1 wt.% is caused by the incorporation of the Au-As clusters, but not because of the formation of Au→Fe solid solution. Therefore, the concentration of "invisible" gold in pyrite is dictated solely by the hydrothermal fluid chemistry and subsequent ore transformations. [ABSTRACT FROM AUTHOR]