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In radiation physics, Monte Carlo radiation transport simulations are powerful tools to evaluate the cellular responses after irradiation. When investigating such radiation-induced biological effects, it is essential to perform track structure simulations by explicitly considering each atomic interaction in liquid water at the sub-cellular and DNA scales. The Particle and Heavy-Ion Transport code System (PHITS) is a Monte Carlo code which enables to calculate track structure at DNA scale by employing the track-structure modes for electrons, protons and carbon ions. In this paper, we review the recent development status and future prospects of the track-structure modes in the PHITS code. To date, the physical features of these modes have been verified using the available experimental data and Monte Carlo simulation results reported in literature. These track-structure modes can be used for calculating microdosimetric distributions to estimate cell survival and for estimating initial DNA damage yields. The use of PHITS track-structure mode is expected not only to clarify the underlying mechanisms of radiation effects but also to predict curative effects in radiation therapy. The results of PHITS simulations coupled with biophysical models will contribute to the radiobiological studies by precisely predicting radiation-induced biological effects based on the Monte Carlo approach. [ABSTRACT FROM AUTHOR]

When many individual atoms come together to form a solid, their interaction splits their electronic energy levels to form continuous bands separated by forbidden energy ranges known as band gaps. Introducing defects in a solid results in new electron energy levels that may lie inside the bandgaps. The presence of these defect levels is the heart of the semiconductor-based devices that play a significant role in the modern world. Quantum mechanics provides the best description of interacting atoms. However, band formation is not unique to small-scale atomic interactions but rather is a result of the wave-nature of Schrödinger's equation, which governs quantum mechanics. Using oscillations in a mass-spring system, we present a table-top, classical analog to the quantum system illustrating how defects in a one-dimensional lattice produce changes to the band structure. A pair of masses connected by a spring plays the role of a single atom. Interactions between "atoms" are introduced with weak coupling springs producing two distinct frequency bands from the translational and fundamental modes. Defects are introduced by altering an oscillator pair's total mass or internal spring constant. We provide the theoretical groundwork and experimental verification of the model along with a discussion of the value and limitations of the model as a macroscopic tool to visualize the microscopic world. [ABSTRACT FROM AUTHOR]

The fragility that controls the temperature-dependent viscous properties of liquids as the glass transition is approached, in various glass-forming liquids with different softness of the repulsive part of atomic interactions at different densities, is investigated by molecular dynamic simulations. We show that the landscape of fragility in purely repulsive systems can be separated into three regions denoted as RI, RII, and RIII, respectively, with qualitatively disparate dynamic behaviors: RI which can be described by "softness makes strong glasses," RII where fragility is independent of softness and can only be tuned by density, and RIII with constant fragility, suggesting that density plays an unexpected role for understanding the repulsive softness dependence of fragility. What is more important is that we unify the long-standing inconsistence with respect to the repulsive softness dependence of fragility by observing that a glass former can be tuned more fragile if nonperturbative attraction is added into it. Moreover, we find that the vastly dissimilar influences of attractive interaction on fragility could be estimated from the structural properties of related zero-temperature glasses. [ABSTRACT FROM AUTHOR]

A complementary measurement method based on a home-built double-sided velocity map imaging setup is introduced. This method can simultaneously obtain time-resolved photoelectron imaging and fragment ion imaging. It has been successfully applied to investigate the ultrafast dynamics of the second singlet electronically excited state (S2) in m-xylene. Time-resolved photoelectron and ion signals derived from the initial populated S2 state are tracked following two-photon absorption of a pump pulse. Time-of-flight mass spectra (TOFMS) show that there are dominant parent ions and one fragment ions with methyl loss during such a process. According to the measured photoelectron images and fragment ions images, transient kinetic energy distributions and angular distributions of the generated photoelectrons and fragments are obtained and analyzed. Compared to stand-alone photoelectron imaging, the obtained fragment ion imaging is powerful for further understanding the mechanisms especially when the dissociation occurs during the pump-probe ionization. Two competing channels intersystem crossing T3 ← S2 and internal conversion S1 ← S2 are attributed to the deactivation of the S2 state. A lifetime of ~50 fs for the initially excited S2 state, of ~276 fs for the secondary populated S1 state, and of 5.76 ps for the T3 state is inferred. [ABSTRACT FROM AUTHOR]

The exponentially correlated Hylleraas‐configuration interaction wave function (E‐Hy‐CI) is a generalization of the Hylleraas‐configuration interaction (Hy‐CI) in which the single rij of an Hy‐CI wave function is generalized to the generic type rijνije−ωijrij. This type of correlation has the right behavior both in the vicinity of the rij cusp and as rij goes to infinity; this work shows that wave functions containing both linear and exponential rij factors converge more rapidly than either one alone for low‐lying excited states of 1S symmetry. E‐Hy‐CI variational calculations with up to 8568 configurations lead to a nonrelativistic energy of −7.2799 1341 2669 3059 6491 6759 hartree for the 1 1S ground state of the Li+ ion. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance (NMR) spectroscopy is a versatile tool for probing structure, dynamics, folding, and interactions at atomic resolution. While naturally occurring magnetically active isotopes, such as 1H, 13C, or 15N, are most commonly used in biomolecular NMR, with 15N and 13C isotopic labeling routinely employed at the present time, 19F is a very attractive and sensitive alternative nucleus, which offers rich information on biomolecules in solution and in the solid state. This perspective summarizes the unique benefits of solution and solid-state 19F NMR spectroscopy for the study of biological systems. Particular focus is on the most recent studies and on future unique and important potential applications of fluorine NMR methodology. [Display omitted] Introduction of a fluorine atom into a protein provides a sensitive probe for probing structure and dynamics by 1D 19F NMR. [ABSTRACT FROM AUTHOR]

Hand-object interaction plays a very important role when humans manipulate objects. While existing methods focus on improving hand-object recognition with fully automatic methods, human intention has been largely neglected in the recognition process, thus leading to undesirable interaction descriptions. To better interpret human-object interaction that is aligned to human intention, we argue that a reference specifying human intention should be taken into account. Thus, we propose a new approach to represent interactions while reflecting human purpose with three key factors, i.e., hand, object and reference. Specifically, we design a pattern of < hand-object, object-reference, hand, object, reference > (HOR) to recognize intention based atomic hand-object interactions. This pattern aims to model interactions with the states of hand, object, reference and their relationships. Furthermore, we design a simple yet effective Spatially Part-based (3+1)D convolutional neural network, namely SP(3+1)D, which leverages 3D and 1D convolutions to model visual dynamics and object position changes based on our HOR, respectively. With the help of our SP(3+1)D network, the recognition results are able to indicate human purposes accurately. To evaluate the proposed method, we annotate a Something-1.3k dataset, which contains 10 atomic hand-object interactions and about 130 videos for each interaction. Experimental results on Something-1.3k demonstrate the effectiveness of our SP(3+1)D network. [ABSTRACT FROM AUTHOR]

To understand the role of mixed soft segments (PCL/PTHF) on the microphase separation of TPUs, thermodynamic calculations, molecular dynamics (MD) simulation and experimental approaches were used. With the use of three-component Flory–Huggins model, interaction parameter and solubility parameters, the free energy of mixing of soft segments and hard segment was investigated. MD simulation was also used to evaluate different types of hydrogen bonding and segmental interactions at atomic levels. To this end, the extent of microphase separation (αsep), state of hydrogen bonding, segment melting enthalpies, crystallization process time and temperature, morphology of soft and hard phases and mechanical properties were fully characterized by ATR-FTIR, DSC, TEM, RMS and tensile techniques. Isothermal and non-isothermal examinations have shown that using mixed soft segments accelerates the microphase separation process comparing samples containing one type of polyols. Mechanical properties data showed that using mixed soft segments disallowed early failure and TPU with extreme enhanced elongation at break and toughness could be obtained. [ABSTRACT FROM AUTHOR]

This paper provides an in-depth study in the various methods for toughening epoxy (EP) resin with polyamide (PA) across a range of length scales—from the atomic to the macroscopic. This allows for a fundamental understanding of the EP-PA system, as many of the atomic interactions and their kinetics inform the macroscopic mechanical properties. The kinetics of the EP-PA reaction prove that covalent bonding is energetically favorable, enabling chemical crosslinking between EP and PA. The two polymers can then mechanically interlock under a number of different processing conditions including forming a homogeneous mixture of the two, incorporating the PA into the EP in the form of fine particles, or adding the PA to an EP-fiber composite. Though each of these methods allows for the tailoring of processing conditions and final structures to an individual use, the literature shows that the underlying physical and chemical interactions can be applied to all EP-PA systems. Thus, lessons learned through the study of one EP-PA structure can be valuable in predicting the behavior of different EP-PA blends and material form combinations. [ABSTRACT FROM AUTHOR]

The article presents the results of calculations of the effective atomic number Z ef for the total atomic cross-section of multi-element substances LiF, MgSO 4 , CaSO 4 ·2H 2 O, CaCO 3 , 3CdSO 4 ·8H 2 O, CaSO 4 , ZnSO 4 , SrSO 4 , CdSO 4 , C 4 H 6 BaO 4 , BaSO 4 , CdWO 4 , Gd 2 O 2 S, PbWO 4 , PbO, UO 2 , UO at photon energies 272.9, 310.5, 320.07, 469.1, 514, and 661.6 keV. The calculation methods differ in parameters and formulas for the approximation of the total atomic cross-section of the interaction of photons with atoms of the substance. An analytical formula is proposed to calculate Z ef. For CaSO 4 ·2H 2 O and the W (65%) Cu alloy, the calculations were carried out in the range of 10–700 keV. Comparison of our results to experimental data and calculations according to the AUTO-Z eff program is carried out. [ABSTRACT FROM AUTHOR]

The Mars Curiosity rover carries an instrument, ChemCam, designed to measure the composition of surface rocks and soil using laser‐induced breakdown spectroscopy (LIBS). The measured spectra from this instrument must be analyzed to identify the component elements in the target sample, as well as their relative proportions. This process, which we call disaggregation, is complicated by so‐called matrix effects, which describe nonlinear changes in the relative heights of emission lines as an unknown function of composition due to atomic interactions within the LIBS plasma. In this work, we explore the use of the plasma physics code ATOMIC, developed at Los Alamos National Laboratory, for the disaggregation task. ATOMIC has recently been used to model LIBS spectra and can robustly reproduce matrix effects from first principles. The ability of ATOMIC to predict LIBS spectra presents an exciting opportunity to perform disaggregation in a manner not yet tried in the LIBS community, namely via Bayesian model calibration. However, using it directly to solve our inverse problem is computationally intractable due to the large parameter space and the computation time required to produce a single output. Therefore, we also explore the use of emulators as a fast solution for this analysis. We discuss a proof of concept Gaussian process emulator for disaggregating two‐element compounds of sodium and copper. The training and test datasets were simulated with ATOMIC using a Latin hypercube design. After testing the performance of the emulator, we successfully recover the composition of 25 test spectra with Bayesian model calibration. [ABSTRACT FROM AUTHOR]

Single-atom-catalysts (SACs) afford a fascinating activity with respect to other nanomaterials for hydrogen evolution reaction (HER), yet the simplicity of single-atom center limits its further modification and utilization. Obtaining bimetallic single-atom-dimer (SAD) structures can reform the electronic structure of SACs with added atomic-level synergistic effect, further improving HER kinetics beyond SACs. However, the synthesis and identification of such SAD structure remains conceptually challenging. Herein, systematic first-principle screening reveals that the synergistic interaction at the NiCo-SAD atomic interface can upshift the d-band center, thereby, facilitate rapid water-dissociation and optimal proton adsorption, accelerating alkaline/acidic HER kinetics. Inspired by theoretical predictions, we develop a facile strategy to obtain NiCo-SAD on N-doped carbon (NiCo-SAD-NC) via in-situ trapping of metal ions followed by pyrolysis with precisely controlled N-moieties. X-ray absorption spectroscopy indicates the emergence of Ni-Co coordination at the atomic-level. The obtained NiCo-SAD-NC exhibits exceptional pH-universal HER-activity, demanding only 54.7 and 61 mV overpotentials at −10 mA cm−2 in acidic and alkaline media, respectively. This work provides a facile synthetic strategy for SAD catalysts and sheds light on the fundamentals of structure-activity relationships for future applications. While single, dispersed atoms enable efficient atomic utilization, controllably preparing single-atom dimers remains challenging. Here, authors prepare nickel-cobalt single-atom dimers as high-performance pH-universal H2 evolution electrocatalysts. [ABSTRACT FROM AUTHOR]

The behavior of lubricants at operational conditions, such as at high pressures, is a topic of great industrial interest. In particular, viscosity and the viscosity-pressure relation are especially important for applications and their determination by computational simulations is very desirable. In this study, we evaluate methods to compute these quantities based on fully atomistic molecular dynamics simulations, which are computationally demanding but also have the potential to be most accurate. We used the 9,10-dimethyloctadecane molecule, main component of PAO-2 base oil as the lubricant for our tests. The methods used for the viscosity simulations are the Green-Kubo equilibrium molecular dynamics (EMD-GK) and nonequilibrium molecular dynamics (NEMD), at pressures of up to 1.0 GPa and various temperatures (40-150 degrees Celsius). We present the theory behind these methods and investigate how the simulation parameters affect the results obtained, to ensure viscosity convergence with respect to the simulation intervals and all other parameters. We show that, by using each method in its regime of applicability, we can achieve good agreement between simulated and measured values. NEMD simulations at high pressures captured zero shear viscosity successfully; while at 40 degrees Celsius, EMD-GK is only applicable to pressures up to 0.3 GPa, where the viscosity is lower. In NEMD, longer and multiply repeated simulations improve the confidence interval of viscosity, which is essential at lower pressures. Another aspect of these methods is the choice of the utilized force field for the atomic interactions. This was investigated by selecting two different commonly used force fields. [ABSTRACT FROM AUTHOR]

Drude weight and optical conductivity of a two-dimensional heavy-hole gas with k-cubic spin-orbit interactions Alestin Mawrie and Tarun Kanti Ghosh Department of Physics, Indian Institute of Technology-Kanpur, Kanpur 208 016, India (Received 22 August 2015; accepted 15 January 2016; published online 28 January 2016) We present a detailed theoretical study on zero-frequency Drude weight and optical conductivity of a two-dimensional heavy-hole gas (2DHG) with k-cubic Rashba and Dresselhaus spin-orbit interactions. The presence of k-cubic spin-orbit couplings strongly modifies the Drude weight in comparison to the electron gas with k-linear spin-orbit couplings. For large hole density and strong k-cubic spin-orbit couplings, the density dependence of Drude weight deviates from the linear behavior. We establish a relation between optical conductivity and the Berry connection. Unlike two-dimensional electron gas with k-linear spin-orbit couplings, we explicitly show that the optical conductivity does not vanish even for equal strength of the two spin-orbit couplings. We attribute this fact to the non-zero Berry phase for equal strength of k-cubic spin-orbit couplings. The least photon energy needed to set in the optical transition in hole gas is one order of magnitude smaller than that of electron gas. Types of two van Hove singularities appear in the optical spectrum are also discussed. [ABSTRACT FROM AUTHOR]

Strong spin-orbit coupled 5d transition metal based ABO3 oxides, especially iridates, allow tuning parameters in the phase diagram and may demonstrate important functionalities, for example, by means of strain effects and symmetry-breaking, because of the interplay between the Coulomb interactions and strong spin-orbit coupling. Here, we have epitaxially stabilized high quality thin films of perovskite (Pv) CaIrO3. Film on the best lattice-matched substrate shows semi-metal-like characteristics. Intriguingly, imposing tensile or compressive strain on the film by altering the underlying lattice-mismatched substrates still maintains semi-metallicity with minute modification of the effective correlation as tensile (compressive) strain results in tiny increases (decreases) of the electronic bandwidth. In addition, magnetoresistance remains positive with a quadratic field dependence. This persistent semi-metal-like nature of Pv-CaIrO3 thin films with minute changes in the effective correlation by strain may provide new wisdom into strong spin-orbit coupled 5d based oxide physics. [ABSTRACT FROM AUTHOR]

Measurement of the magnetic hyperfine fields in metallic thin wires under spin Hall conditions was attempted using the emerging technique, synchrotron-radiation Mössbauer spectroscopy. A Mössbauer probe layer of 57Fe (0.2 nm), 57Fe (0.6 nm), or 119Sn (0.6 nm) was embedded as an electron spin detector near the surfaces of V, Au, Pt, and 56Fe wires. The magnitudes of the magnetic hyperfine fields at the 57Fe and 119Sn nuclear sites that could be enhanced by non-equilibrium conduction- electron spin polarization were measured both without and with the application of an electric current along the wire. Changes in the Mössbauer spectra were not clearly observed, indicating that the magnetic hyperfine field induced by non-equilibrium spin polarization is smaller than the detection limit at least for the measured systems and conditions. [ABSTRACT FROM AUTHOR]

Effect of isoelectronic substitution of In for Ga on the phase transition and magnetic properties was studied in Ni57Mn18Ga25-xInx (0 ⩽ x ⩽ 8) alloys. With the increasing In content, the roomtemperature phase structure evolved from tetragonal martensite to cubic austenite. The martensitic transformation temperatures were significantly decreased by the substitution of In for Ga, but the austenitic Curie temperature was only slightly decreased. Especially, both thermal and isothermal magnetization measurements revealed that the Curie temperature and saturation magnetization of the martensite were independent on the isoelectronic substitution. The results were discussed by considering the phase structures and the atomic interactions. [ABSTRACT FROM AUTHOR]

This work gives new evidence on the structural properties of tetragonal hybrid perovskites obtained from different experimental routes of synthesis, and the theoretical elucidation of their electronic structure properties in accordance to the formation of the energy band gaps. Two different synthesis routes to prepare hybrid perovskites of the form (CH 3 NH 3 PbI 3) have been performed. The final crystal structure depends on the conditions of the preparation method that give the perovskite a twisted or regular molecular structure. This was certified by the structural analysis, normal modes of vibration, and opto-electronic properties. Moreover, the elucidation of electronic structure properties were also analyzed by a first principles study. That is, density functional theory (DFT) calculations revealed the structure configuration of twisted hybrid perovskites CH 3 NH 3 PbI 3 , in combination with XRD evidence. The electronic structure properties of the systems under study are mainly ruled by the geometrical disposition of the organic cation, whose different degrees of freedom are intimately related to the size of the energy band gap, and also to the magnitude of the work function. The DFT analysis with the experimental characterization of these hybrid perovskite systems could aid to tailor novel materials intended to be applied in the new generation of solar cell devices. That is, our combined methodology could contribute to modify the structure of perovskites with improved electronic properties for solar energy applications. [Display omitted] • The slow solvent evaporation process showed an iodine atom deviation. • CH 3 NH 3 PbI 3 optoelectronic properties were impacted by two synthesis methods. • DFT calculations revealed that the organic cation plays a role on gap formation. • Theoretical work functions are sensitive to the atomic interactions with the substrate. • Absorption spectra showed that twisted perovskites could act as an absorber material. [ABSTRACT FROM AUTHOR]

Biomolecular phase separation that contributes to the formation of membraneless organelles and biomolecular condensates has recently gained tremendous attention because of the importance of these assemblies in physiology, disease, and engineering applications. Understanding and directing biomolecular phase separation requires a multiscale view of the biophysical properties of these phases. Yet, many classic tools to characterize biomolecular properties do not apply in these condensed phases. Here, we discuss insights obtained from spectroscopic methods, in particular nuclear magnetic resonance and optical spectroscopy, in understanding the molecular and atomic interactions that underlie the formation of protein-rich condensates. We also review approaches closely coupling nuclear magnetic resonance data with computational methods especially coarse-grained and all-atom molecular simulations, which provide insight into molecular features of phase separation. Finally, we point to future methodolical developments, particularly visualizing biophysical properties of condensates in cells. [ABSTRACT FROM AUTHOR]

An X‐ray diffraction study aimed at establishing the subtle details of the electron density and anharmonicity of the atomic vibrations in a stoichiometric monodomain single crystal of potassium niobate, KNbO3, has been conducted at room temperature (orthorhombic ferroelectric phase Amm2). The cation and anion displacements obtained from the experiment are weakly anharmonic without any manifestation of structural disorder. The chemical bond and interatomic interactions inside and between crystal substructures at the balance of intracrystalline forces are characterized in detail. The role of each of the ions in the formation of the ferroelectric phase was studied and the features of the electron‐density deformation in the niobium and oxygen substructures, and the role of each of them in the occurrence of spontaneous polarization are established. The position‐space distribution of electrostatic and quantum forces in KNbO3 is restored. It is emphasized that for the completeness of the analysis of the nature of the ferroelectric properties it is necessary to consider both static and kinetic electronic factors, which are of a quantum origin. The experimental results and theoretical estimations by the Kohn–Sham calculation with periodic boundary conditions are in reasonable agreement, thus indicating the physical significance of the findings of this study. [ABSTRACT FROM AUTHOR]

An X‐ray diffraction study aimed at establishing the subtle details of the electron density and anharmonicity of the atomic vibrations in a stoichiometric monodomain single crystal of potassium niobate, KNbO3, has been conducted at room temperature (orthorhombic ferroelectric phase Amm2). The cation and anion displacements obtained from the experiment are weakly anharmonic without any manifestation of structural disorder. The chemical bond and interatomic interactions inside and between crystal substructures at the balance of intracrystalline forces are characterized in detail. The role of each of the ions in the formation of the ferroelectric phase was studied and the features of the electron‐density deformation in the niobium and oxygen substructures, and the role of each of them in the occurrence of spontaneous polarization are established. The position‐space distribution of electrostatic and quantum forces in KNbO3 is restored. It is emphasized that for the completeness of the analysis of the nature of the ferroelectric properties it is necessary to consider both static and kinetic electronic factors, which are of a quantum origin. The experimental results and theoretical estimations by the Kohn–Sham calculation with periodic boundary conditions are in reasonable agreement, thus indicating the physical significance of the findings of this study. [ABSTRACT FROM AUTHOR]

It is known that, in the strong electric field, electrons undergo continuous acceleration [runaway electrons (REs)] even in dense media, receiving from the field more energy than lose via interactions with the ambient atomic particles. We, here, analyze the effect of the angular scattering of electrons in inelastic interactions on the runaway process. For this purpose, we developed a Monte Carlo (MC) code and, having carried out simulations of electron transport in the helium of atmospheric density, calculated the runaway rate at the field strengths of 50–300 kV cm−1. We show that different models of the electron scattering lead to a tenfold difference in the runaway rate magnitudes. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) based drug design has demonstrated great potential to fundamentally change the pharmaceutical industries. Currently, a key issue in AI-based drug design is efficient transferable molecular descriptors or fingerprints. Here, we present hypergraph-based molecular topological representation, hypergraph-based (weighted) persistent cohomology (HPC/HWPC) and HPC/HWPC-based molecular fingerprints for machine learning models in drug design. Molecular structures and their atomic interactions are highly complicated and pose great challenges for efficient mathematical representations. We develop the first hypergraph-based topological framework to characterize detailed molecular structures and interactions at atomic level. Inspired by the elegant path complex model, hypergraph-based embedded homology and persistent homology have been proposed recently. Based on them, we construct HPC/HWPC, and use them to generate molecular descriptors for learning models in protein–ligand binding affinity prediction, one of the key step in drug design. Our models are tested on three most commonly-used databases, including PDBbind-v2007, PDBbind-v2013 and PDBbind-v2016, and outperform all existing machine learning models with traditional molecular descriptors. Our HPC/HWPC models have demonstrated great potential in AI-based drug design. [ABSTRACT FROM AUTHOR]

This short paper shows that Rutherford first discussed in 1906, when he was at McGill, the possibility of determining the structure of the atom by measuring the diffusion of alpha particles in an experiment used to measure the retardation of alpha particles when passing through matter. The famous experiments of Geiger and Marsden that led to the discovery of the atomic nucleus by Rutherford in 1911 is then presented. That is followed by a discussion of some of the very early works of colleagues of Rutherford that improved on these early experiments in order to determine the size of the atomic nucleus and the interaction that held the nucleus together. Finally. a list of the main early improvements to the interpretations of nucleus-nucleus scattering is presented. [ABSTRACT FROM AUTHOR]

Background: Surface topography strongly modifies adhesion of hard-material contacts, yet roughness of real surfaces typically exists over many length scales, and it is not clear which of these scales has the strongest effect. Objective: This investigation aims to determine which scales of topography have the strongest effect on macroscopic adhesion. Methods: Adhesion measurements were performed on technology-relevant diamond coatings of varying roughness using spherical ruby probes that are large enough (0.5-mm-diameter) to sample all length scales of topography. For each material, more than 2000 measurements of pull-off force were performed in order to investigate the magnitude and statistical distribution of adhesion. Using sphere-contact models, the roughness-dependent effective values of work of adhesion were measured, ranging from 0.08 to 7.15 mJ/m2 across the four surfaces. The data was more accurately fit using numerical analysis, where an interaction potential was integrated over the AFM-measured topography of all contacting surfaces. Results: These calculations revealed that consideration of nanometer-scale plasticity in the materials was crucial for a good quantitative fit of the measurements, and the presence of such plasticity was confirmed with AFM measurements of the probe after testing. This analysis enabled the extraction of geometry-independent material parameters; the intrinsic work of adhesion between ruby and diamond was determined to be 46.3 mJ/m2. The range of adhesion was 5.6 nm, which is longer than is typically assumed for atomic interactions, but is in agreement with other recent investigations. Finally, the numerical analysis was repeated for the same surfaces but this time with different length-scales of roughness included or filtered out. Conclusions: The results demonstrate a critical band of length-scales—between 43 nm and 1.8 µm in lateral size—that has the strongest effect on the total adhesive force for these hard, rough contacts. [ABSTRACT FROM AUTHOR]

Combining different semiconductor materials with diverse geometric structures and energy level configurations is an effective strategy for constructing heterostructured photocatalysts with high activity. Using a solvothermal method, 1D TiO2 nanobelts were uniformly embedded into the gaps of flower-like 3D ZIS/MoS2 microspheres to allow atomic interactions. Therefore, a 3D ZnIn2S4–MoS2 microsphere/1D TiO2 nanobelt (ZIS/MoS2/TiO2) composite with outstanding hydrogen production performance was synthesized. The unique heterostructure had a favorable energy level distribution and spatial structure, which could improve the interfacial charge transfer. Upon optimizing the weight ratios of the components, the maximum photocatalytic H2 evolution rate was 8440.28 μmol g−1 h−1 when using the 250%-ZIS/25%-MoS2/TiO2 composite under simulated sunlight irradiation, which was ∼44.4 and 2181.0 times higher than when using pure ZIS and TiO2, respectively. In addition, apparent quantum efficiency (AQE) values of 39.33% at 380 nm and 30% at 420 nm were achieved. Importantly, the hydrogen production rate was 94.1% of the initial rate after four cycles, showing excellent stability. The photocatalytic hydrogen evolution mechanism of the prepared photocatalyst was also discussed in detail. [ABSTRACT FROM AUTHOR]

Active element Ti plays a crucial role in the graphite soldering process. However, the atomic interaction mechanism between the active element Ti and graphite remains unclear. In this study, the enhancement effect of the active element Ti on the Sn-based alloy filler/graphite soldering interface was investigated by employing first-principles calculations combined with experimental methods. Based on the first-principles calculations, the adhesion work of the Sn/graphite interface models doped with two and four Ti atoms is 0.884 J/m2 and 1.896 J/m2, respectively, while that of the clean model is negative. Moreover, the segregation heat of the Sn/graphite interface model doped with more Ti atoms is more negative. All of these results indicate that Ti atoms doped at the Sn/graphite interface play a significant role in enhancing the interface. The electronic structures of the interface models with different numbers of titanium atoms were analyzed. The results revealed that the enhancement of the Sn/graphite interface was attributed to the transfer of electrons from the Ti-3d orbitals to the C-2p orbitals, leading to a strong interaction between the Ti and C atoms. The segregation of Ti was clearly observed at the Sn3·5Ag4Ti (Ce,Ga)/graphite soldering interface in the experiments, which was consistent with the results from the first-principles calculations. The shear strength of the Sn3·5Ag4Ti (Ce,Ga)/graphite soldered joint was tested, and an enriched region of titanium was found in the fracture surface on the graphite side. In addition, a tensile simulation was performed on the clean and Ti-doped Sn/graphite interfaces, and the results indicated that the Sn/graphite interface model enriched with Ti atoms had greater tensile simulation strength than that of the clean Sn/graphite interface model. These results further showed that Ti played a reinforcing role at the Sn/graphite interface. The results from our study provide a theoretical basis for exploring low-temperature active bonding methods in the packaging process of graphite connected to the heat dissipation surface of electronic devices. • The mechanism of Ti-enhanced soldering interfaces is explored on the atomic scale. • Both adhesion work and heat segregation suggest Ti enhances the interface. • Electron transfer in Ti-3d and C-2p orbitals causes a strong Ti–C interaction. • The segregation of Ti is found and it may be the key factor for successful bonding. [ABSTRACT FROM AUTHOR]

SIRT6 is of interest for its promising effect in the treatment of aging-related diseases. Studies have shown quercetin (QUE) and its derivatives have varying degrees of effect on the catalytic effect of SIRT6. In the research, the effect of QUE on the protein-substrate interaction in the SIRT6-mediated mono-ADP ribosylation system was investigated by conventional molecular dynamics (MD) simulations combined with MM/PBSA binding free energy calculations. The results show that QUE can bind stably to SIRT6 with the binding energy of −22.8 kcal/mol and further affect the atomic interaction between SIRT6 and NAD+ (or H3K9), resulting in an increased affinity between SIRT6-NAD+ and decreased SIRT6-H3K9 binding capacity. At the same time, the binding of QUE can also alter some structural characteristics of the protein, with large shifts occurring in the residue regions involving the N-terminal (residues 1–27), Rossmann fold regions (residues 55–92), and ZBD (residues 164–179). Thus, QUE shows great potential as a scaffold for the design of novel potent SIRT6 modulators. The binding of Quercetin with SIRT6 affects the protein-ligand interaction in the SIRT6-mediated mono-ADP ribosylation system. [Display omitted] • Quercetin and its derivatives affect protein-substrate interactions in the SIRT6-mediated mono-ADP ribosylation reaction. • Quercetin has a binding energy of −22.8 kcal/mol and may attach to SIRT6 steadily. • Quercetin results in an increased affinity between SIRT6-NAD+ and decreased SIRT6-H3K9 binding capacity. • The binding of quercetin results in alterations to the structural characteristics of the SIRT6 protein. [ABSTRACT FROM AUTHOR]

The energy storage sector requires high capacity, long cycling life batteries. Silicon (Si) arises as a pivotal anode material for next-generation lithium-ion batteries owing to its exceptional capacity. However, challenges arise from lithium interactions, causing volumetric expansion and structural concerns like cracking. Si anodes also exhibit diverse phenomena during lithiation, influenced by crystal orientations. A thorough comprehension of the (de)lithiation process is essential to address challenges, despite existing gaps in knowledge, with strategic design and complementary materials, offering potential solutions by enhancing ion mobility and minimizing diffusion barriers. Here we have developed and applied first-principles simulations to offer fundamental insights into atomic interactions, providing a realistic atomistic representation of lithiation processes. Our simulations systematically incorporate Li+ into Si and Si- nitrogen vacancies (NV) orientations, and evaluation between Si and Si-NV (110) indicates a more favorable behavior in ionic diffusion for Si-NV(110), with a range of 2.55 × 10−3 to 1.64 × 10−2 (cm2/s) and a 15 % decrease in volume expansion. Our results explain the ternary Si–Li–N electrode materials and the identification of optimal site disorders to maximize the rate of Li+ diffusion in crystalline Si anodes. [Display omitted] • Comparing the Formation energy of Si and Si-NV facets. • Analysis of the evolution of the structure and volume expansion effects, surface dependency & defects' influence during electrode lithiation. • Role of Diffusion Anisotropy in diffusion barriers of Si and Si-NV facets. [ABSTRACT FROM AUTHOR]

MgB 2 has a wide range of applications as a crucial superconducting material in fields such as electronics and communications, but its weak mechanical properties limit its use in extreme environments such as high pressure. Therefore, this article explores the enhancement mechanism of the mechanical properties for MgB 2 by substituting Mg sites with Nb element based on first principles. After substitution, NbB 2 has better thermodynamic stability, and the introduction of Nb-d state enhances light absorption. In terms of mechanics, due to the higher electron accumulation density in the Nb–B bond and a shorter bond length (2.451 Å), the atomic interactions become tighter and stronger. As a result, both elastic constants and modulus are enhanced, exhibiting high stiffness, high compression resistance, etc. The spatial distribution of 3D elastic anisotropy is closer to a spherical shape and the universal anisotropy index (A U ) tends to approach 0, which indicates the mechanical properties in all directions are more consistent, making it easier to predict and control. Meanwhile, the elastic modulus rises smoothly with increasing hydrostatic pressure and is not affected by lattice compression at low hydrostatic pressure. The change rate of B–B bond length is 6.8 % at 100 GPa, which becomes the main reason for the enhancement of mechanical properties. The article provides a theoretical foundation for the preparation of superconductors with excellent mechanical properties under extreme conditions. [ABSTRACT FROM AUTHOR]

The processes involved in the high-pressure phases of Sr–S compounds and the pressure-induced decomposition into strontium and sulfur are investigated using a structure prediction approach combined with first-principles calculations. The compression of Sr–S compound leads to its decomposition into strontium and sulfur at 794 GPa, which contradicts the general intuition that pressure stabilizes and densifies materials. With increasing pressure, the combined effect of the ΔPV and ΔU term increases the enthalpy difference, ultimately leading to the decomposition of the Sr–S compound. Moreover, the analysis based on molecular orbital theory reveals that pressure induces an increased population of antibonding states, consequently reducing the stability of the compound and promoting its decomposition. Furthermore, the analysis of atomic interactions reveals that under pressure, the reduction of charge transfer between atoms causes a decrease in electrostatic interactions, thereby weakening the stability of the compound and resulting in its decomposition into strontium and sulfur atoms. This work not only demonstrates the high-pressure properties of Sr–S compounds but also provides insight into understanding other high-pressure alkaline-earth sulfides. [ABSTRACT FROM AUTHOR]

We designed a new microstructure control method (liquid metal replacement method) that creates entirely new composites using the original microstructure as a template. This method selectively replaces a specific phase from a composite with another phase based on differences in atomic interactions. We applied this method to the dissimilar material joining of immiscible titanium and magnesium. After diffusion bonding one side of an interlayer consisting of α-Ti / α-Sc phases to Ti, we butted the opposite side with Mg and reheated. At this interface, selective interdiffusion of Mg and Sc results in the replacement of only the α-Sc phase by the α-Mg phase, forming a new α-Ti / α-Mg bicontinuous microstructure using the α-Ti / α-Sc monotectoid microstructure as a template. The Sc that diffused to the Mg side formed a reaction layer where the MgSc (B2) and (Mg, Sc) solid solution coexisted. These novel composite structures and reaction layers strengthened the joint area. As a result, we suppressed fracture at the joint interface, causing fracture at Mg and achieving a maximum joint strength of 116 MPa. [Display omitted] • We welded dissimilar titanium and magnesium through a scandium-containing interlayer. • The magnesium melts selectively replaced specific phases of the Ti/Sc microstructure. • A three-dimensional bicontinuous microstructure of immiscible Ti/Mg phases formed at the joint interface. • We studied the relationship between the interlayer composition and tensile strength. [ABSTRACT FROM AUTHOR]

Theoretical prediction of sputtering yields of a material subject to ion bombardment requires a detailed knowledge of how atoms in the material interact with other atoms moving with high kinetic energies. In this study, molecular-dynamical (MD) simulations were performed to predict the self-sputtering yields of nickel (Ni) for an incident ion energy ranging from 100 to 4000 eV, modifying existing interatomic potential (or force-field) functions designed for bulk Ni metal in thermal equilibrium. The selection of Ni as a sample material was motivated by an interest in developing damageless etching processes for ferromagnetic materials used in semiconductor devices. The simulations were performed until the system reaches steady state, where surface roughness formed self-consistently owing to the ion bombardment. It has been found that, for high-energy impact, the short-distance atomic repulsion plays a key role in determining the sputtering yields. The Ni self-sputtering yields predicted by the MD simulations of this study were found to be in reasonable agreement with experimental yield data. However, it was also found that two interatomic potential models for Ni that gave essentially the same mechanical properties of metallic Ni gave largely different sputtering yield values. These observations indicate that, for an existing interatomic model to be used effectively to predict sputtering yields of a material by MD simulation, it, in general, requires further modification to represent atomic interactions away from the thermodynamic equilibrium positions. [ABSTRACT FROM AUTHOR]

This study combines cryo‐photoelectron spectroscopy and electrochemical analysis techniques to investigate the p‐Si/SiO2/TiO2/H2O system in the context of water‐splitting. Atomic layer deposition is used for the preparation of a TiO2 thin film coating for a p‐Si/SiO2 photocathode. First, an interface experiment is performed to study the contact properties of the interface between p‐Si/SiO2 and TiO2. For the p‐Si/TiO2 heterojunction, a downward band bending of 0.3 eV is found for the p‐Si toward the interface. Second, a water adsorption experiment is conducted, which allows the investigation of the surface chemistry of the TiO2 coating in contact to water. A direct correlation between the amount of surface hydroxide species, formed due to water dissociation, and Ti3+ defect state density is found. Furthermore, a surface water species can be identified in addition to the commonly found bulk molecular water. Together with the results from a Mott–Schottky analysis, a complete energy level alignment can be constructed. [ABSTRACT FROM AUTHOR]

All‐inorganic perovskite cesium lead iodide (CsPbI3) exhibits excellent prospects for commercial application as a light absorber in single‐junction or tandem solar cells due to its outstanding thermal stability and proper bandgap. However, the device performance of CsPbI3‐based perovskite solar cells (PSCs) is still restricted by the unsatisfactory crystal quality and severe non‐radiative recombination. Herein, inorganic additive ammonium halides are introduced into the precursor solution to regulate the nucleation and crystallization of the CsPbI3 film by exploiting the atomic interaction between the ammonium group and the Pb–I framework. The grain boundaries and interfacial contact of the CsPbI3 film have been improved, which leads to significant suppression in the non‐radiative recombination and an enhancement in the charge transport ability. With these benefits, a high efficiency of 18.7% together with an extraordinarily high fill factor of 0.83–0.84 has been achieved, comparable to the highest records reported so far. Moreover, the cell exhibits ultra‐high photoelectrical stability under continuous light illumination and high bias voltage with 96% of its initial power‐conversion efficiency being sustained after 2000 h operation, even superior to the world‐champion CsPbI3 solar cell. The findings are promising for the development and application of all‐inorganic PSCs using a simple inorganic additive strategy. [ABSTRACT FROM AUTHOR]

Refining modelled structures to approach experimental accuracy is one of the most challenging problems in molecular biology. Despite many years' efforts, the progress in protein or RNA structure refinement has been slow because the global minimum given by the energy scores is not at the experimentally determined "native" structure. Here, we propose a fully knowledge-based energy function that captures the full orientation dependence of base–base, base–oxygen and oxygen–oxygen interactions with the RNA backbone modelled by rotameric states and internal energies. A total of 4000 quantum-mechanical calculations were performed to reweight base–base statistical potentials for minimizing possible effects of indirect interactions. The resulting BRiQ knowledge-based potential, equipped with a nucleobase-centric sampling algorithm, provides a robust improvement in refining near-native RNA models generated by a wide variety of modelling techniques. Predicting RNA structure from sequence is challenging due to the relative sparsity of experimentally-determined RNA 3D structures for model training. Here, the authors propose a way to incorporate knowledge on interactions at the atomic and base–base level to refine the prediction of RNA structures. [ABSTRACT FROM AUTHOR]

The gelation of waxy crude oil multiphase system can result in the formation of network cementitious structure, which seriously impacts the safe and economic production of crude oil. This paper reviews current experimental, theoretical and numerical results on the gelation of wax in crude oil. For the experimental side, the most important problems are in situ measurement and measurement accuracy. On the theoretical side, the present methods own defects of low accuracy and limited application scope. Numerically, the models are of oversimplification, which are hardly applied to the real production. Besides, as a promising solution, the research progress of crude oil pour point depressant is also reviewed. The molecular design is a powerful approach to develop the optimized pour point depressant. The goals of this paper are to bridge the microscale atomic interactions and the macroscale physicochemical properties of waxy crude oil and pour point depressant, so as to lay a solid theoretical basis for preventing and controlling wax deposition in crude oil. These are beneficial to the future efficient, clean and safe energy production system. [ABSTRACT FROM AUTHOR]

The abounding use of cobalt oxide nanoparticles (Co3O4) requires a detailed understanding of their environmental and biomedical nanotoxicity and an eminent solution to the associated hazards; molecular and atomic aspects of the subject are poorly understood. This study reconnoiters the in vitro and in vivo nanotoxicity of Co3O4 nanoparticles using human colon cell lines and the embryonic zebrafish model. The synthesis of Co3O4 nanoparticles (G-CoONP) is delineated via the deployment of a medicinal herb, Calotropis gigantea, as an alternative greener solution; stable G-CoONP with a size of 41 ± 15 nm are attainable. Gas chromatography-mass spectroscopy (GCMS) analysis revealed the role of floral extract biomolecules in G-CoO NP synthesis. The in vitro and in vivo effects are accompanied by dose-dependent exposure at the molecular level by eliciting Sod1 and P53 genes up to 8.2 and 5.2 fold leading to a significant change in the reactive oxygen species and apoptosis level. It unraveled the toxicity of the cobalt oxide NP as increased apoptosis elicited by higher oxidative stress due to the accumulation and internalization of nanoparticles in cells and embryos. Green synthesized G-CoONP exhibited higher biocompatibility than commercial C-CoONP with reduced apoptosis and ROS in both human colon cell lines and zebrafish embryos. In silico analysis portrayed the intrinsic atomic interaction of Co3O4 NP with cysteine, arginine, and histidine of oxidative stress (SOD1/sod1) and apoptosis (TP53/tp53) proteins leading to dysregulation of their structural and functional integrity in human and zebrafish, respectively. A proximal discrepancy in intrinsic atomic interaction due to the H-bonding and hydrophobic interaction at the differential in vitro and in vivo vicinage served as a key determinant factor for the cellular biocompatibility of Co3O4 nanoparticles. [ABSTRACT FROM AUTHOR]

We investigate the emergence of rigid polycrystalline structures from atomistic particle systems. The atomic interaction is governed by a suitably normalized pair interaction energy, where the 'sticky disk' interaction potential models the atoms as hard spheres that interact when they are tangential. The discrete energy is frame invariant and no underlying reference lattice on the atomistic configurations is assumed. By means of Γ -convergence, we characterize the asymptotic behavior of configurations with finite surface energy scaling in the infinite particle limit. The effective continuum theory is described in terms of a piecewise constant field delineating the local orientation and micro-translation of the configuration. The limiting energy is local and concentrated on the grain boundaries, that is, on the boundaries of the zones where the underlying microscopic configuration has constant parameters. The corresponding surface energy density depends on the relative orientation of the two grains, their microscopic translation misfit, and the normal to the interface. We further provide a fine analysis of the surface energies at grain boundaries both for vacuum–solid and solid–solid phase transitions. The latter relies fundamentally on a structure result for grain boundaries showing that, due to the extremely brittle setup, interpolating boundary layers near cracks are energetically not favorable. [ABSTRACT FROM AUTHOR]

A set of advanced characterization methods, including high-resolution X-ray diffraction (measurements and simulations), cross-sectional scanning tunneling microscopy, and high-angle annular dark-field scanning transmission electron microscopy is applied to quantify the interface roughness and atomic intermixing (in both cation and anion sub-lattices) in short period (6-7 nm) InAs/GaSb superlattices intended for mid-wavelength (M) and long-wavelength (L) infrared detectors. The undesired atomic intermixing and interface roughness in the L-samples were found to be considerably lower than in the M-samples. In all specimens, anion intermixing is much higher than that in the cation sub-lattice. Possible origins of these findings are discussed. [ABSTRACT FROM AUTHOR]

The effects of Stone-Wales (SW) and vacancy defects on the failure behavior of boron nitride nanotubes (BNNTs) under tension are investigated using molecular dynamics simulations. The Tersoff-Brenner potential is used to model the atomic interaction and the temperature is maintained close to 300 K. The effect of a SW defect is studied by determining the failure strength and failure mechanism of nanotubes with different radii. In the case of a vacancy defect, the effect of an N-vacancy and a B-vacancy is studied separately. Nanotubes with different chiralities but similar diameter is considered first to evaluate the chirality dependence. The variation of failure strength with the radius is then studied by considering nanotubes of different diameters but same chirality. It is observed that the armchair BNNTs are extremely sensitive to defects, whereas the zigzag configurations are the least sensitive. In the case of pristine BNNTs, both armchair and zigzag nanotubes undergo brittle failure, whereas in the case of defective BNNTs, only the zigzag ones undergo brittle failure. An interesting defect induced plastic behavior is observed in defective armchair BNNTs. For this nanotube, the presence of a defect triggers mechanical relaxation by bond breaking along the closest zigzag helical path, with the defect as the nucleus. This mechanism results in a plastic failure. [ABSTRACT FROM AUTHOR]

The objective of this research is to explore the formation/binding energetics and length scales associated with the interaction between HenV clusters and grain boundaries in bcc α-Fe. In this work, we calculated formation/binding energies for 1–8 He atoms in a monovacancy at all potential grain boundary (GB) sites within 15Å of the ten grain boundaries selected (122106 simulations total). The present results provide detailed information about the interaction energies and length scales of 1–8 He atoms with grain boundaries for the structures examined. A number of interesting new findings emerge from the present study. First, the Σ3(112) "twin" GB has significantly lower binding energies for all HenV clusters than all other boundaries in this study. For all grain boundary sites, the effect of the local environment surrounding each site on the HenV formation and binding energies decreases with an increasing number of He atoms in the HenV cluster. Based on the calculated dataset, we formulated a model to capture the evolution of the formation and binding energy of HenV clusters as a function of distance from the GB center, utilizing only constants related to the maximum binding energy and the length scale. [ABSTRACT FROM AUTHOR]

We determined the Stillinger-Weber interatomic potential parameters for Si/N/H system based on first principles density functional calculations. This new potential can be used to perform classical molecular dynamics simulation for silicon nitride deposition on Si substrate. During the first principles calculations, cluster models have been carefully and systematically chosen to make sampling of the interatomic potential supersurface more thoroughly. Global optimization method was used to fit the ab initio data into Stillinger-Weber form. We used a recursive method to perform the classical molecular dynamics simulations for silicon nitride (SiN) film growth on Si substrate with SiH4/NH3 gas mixtures. During the simulation, we could clearly observe the silicon nitride film growth progress. In this paper, we present the details of potential derivation and simulation results with different SiH4:NH3 ratios. It is demonstrated that this new potential is suitable to describe the surface reactions of the Si/N/H system and allows us to explore more complex SiN growing process such as plasma-enhanced chemical vapor deposition. [ABSTRACT FROM AUTHOR]

We determined the Stillinger-Weber interatomic potential parameters for Si/N/H system based on first principles density functional calculations. This new potential can be used to perform classical molecular dynamics simulation for silicon nitride deposition on Si substrate. During the first principles calculations, cluster models have been carefully and systematically chosen to make sampling of the interatomic potential supersurface more thoroughly. Global optimization method was used to fit the ab initio data into Stillinger-Weber form. We used a recursive method to perform the classical molecular dynamics simulations for silicon nitride (SiN) film growth on Si substrate with SiH4/NH3 gas mixtures. During the simulation, we could clearly observe the silicon nitride film growth progress. In this paper, we present the details of potential derivation and simulation results with different SiH4:NH3 ratios. It is demonstrated that this new potential is suitable to describe the surface reactions of the Si/N/H system and allows us to explore more complex SiN growing process such as plasma-enhanced chemical vapor deposition. [ABSTRACT FROM AUTHOR]

In this study we aim to determine the origin of the electron density describing a CH···HC interaction in planar and twisted conformers of biphenyl. In order to achieve this, the fragment, atomic, localized, delocalized, intra‐ and inter‐atomic (FALDI) decomposition scheme was utilized to decompose the density in the inter‐nuclear region between the ortho‐hydrogens in both conformers. Importantly, the structural integrity, hence also topological properties, were fully preserved as no 'artificial' partitioning of molecules was implemented. FALDI‐based qualitative and quantitative analysis revealed that the majority of electron density arises from two, non‐classical and non‐local effects: strong overlap of ortho CH σ‐bonds, and long‐range electron delocalization between the phenyl rings and ortho carbons and hydrogens. These effects resulted in a delocalized electron channel, that is, a density bridge or a bond path in a QTAIM terminology, linking the H‐atoms in the planar conformer. The same effects and phenomena are present in both conformers of biphenyl. We show that the CH···HC interaction is a molecular‐wide event due to large and long‐range electron delocalization, and caution against approaches that investigate CH···HC interactions without fully taking into account the remainder of the molecule. [ABSTRACT FROM AUTHOR]

Although the atomic catalyst has attracted intensive attention in the past few years, the current progress of this field is still limited to a single atomic catalyst (SAC). With very few successful cases of dual atomic catalysts (DACs), the most challenging part of experimental synthesis still lies in two main directions: the thermodynamic stability of the synthesis and the optimal combination of metals. To address such challenges, comprehensive theoretical investigations on graphdiyne (GDY)‐based DAC are proposed by considering both, the formation stability and the d‐band center modifications. Unexpectedly, it is proven that the introduction of selected lanthanide metals to the transition metals contributes to the optimized stability and electroactivity. With further verification by machine learning, the potential f–d orbital coupling is unraveled as the pivotal factor in modulating the d‐band center with enhanced stability by less orbital repulsive forces. These findings supply the delicate explanations of the atomic interactions and screen out the most promising DAC to surpass the limitations of conventional trial and error synthesis. This work has supplied an insightful understanding of DAC, which opens up a brand new direction to advance the research in atomic catalysts for broad applications. [ABSTRACT FROM AUTHOR]

A systematic synchrotron high‐pressure X‐ray powder diffraction study of Mn3Sn up to 9 GPa is reported. In this pressure range, the crystal symmetry remains in the hexagonal P63/mmc space group, with a continuous reduction of the lattice parameters. Analysis indicates that the Mn3Sn system may have a different magnetic ground state above 4 GPa due to varying local atomic interactions. This is brought about by the slightly varying compression rate for the in‐plane a‐ and out‐of‐plane c‐axis, respectively, ≈−0.0235 and ≈−0.0176 Å GPa−1. The results contribute to the understanding of the crystal structure to the external continuous tuning parameter pressure, which modulates the geometrical arrangement of the atomic species in Mn3Sn, thus impacting the interesting physical properties such as the large anomalous Hall effect. [ABSTRACT FROM AUTHOR]

Recent experimental observations of spin–orbit coupling (SOC) in Bose–Einstein condensates (BECs) open the way for investigating novel physics of nonlinear waves with promising applications in atomic physics and condensed matter physics. The interplay between atomic interactions and SOC are crucial for the understanding of the dynamics of nonlinear waves in BECs with SOC. Here, in the small linear coupling regime, an approach is presented which allows us to derive an infinite number of novel approximate solutions of the Gross–Pitaevskii equations (GPEs) in one and two dimensions including SOCs, time-dependent external potentials, and nonlinearities leading to breathers and periodic as well as quasiperiodic nonlinear waves. To verify the theoretical predictions we perform numerical simulations which show for several cases a very good agreement with the analytics. For the case of one spatial dimension, it is shown that functions describing the external potential and nonlinearities cannot be chosen independently. The management of the solutions is clarified along with some important physical properties such as Josephson oscillations and Rosen–Zener oscillations. [ABSTRACT FROM AUTHOR]