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The single-sited metallocene catalyst has attracted significant attention due to its high activity and application in olefin polymerization industry. In this work, we introduced a strategy of in situ modification of metallocene catalyst with pyrene through π–π stacking to study the effect in olefin polymerization. After activated by MMAO, the pyrene-modified metallocene catalyst exhibited high activities (up to 1333 kg mol−1 h−1) in ethylene polymerization, which was 1.9 times higher than that of the pyrene free catalyst system. This could be because the electron-donating ability of cyclopentene to the transition metal was enhanced through π–π interaction of pyrene with cyclopentene. The copolymerization of ethylene and 1-hexene was also studied. The pyrene-modified metallocene catalyst system performs with higher activity in the copolymerization with a lower monomer incorporation ratio. Density functional theory (DFT) calculations indicated the formation of π–π interaction between the Zr center with pyrene molecule leading to the increase in steric hindrance and electron density. [ABSTRACT FROM AUTHOR]

Context: We rationalize the excellent performance of information-theoretic descriptors for predicting atomic and molecular polarizabilities. It seems that descriptors which capture information about the change in valence-shell structure, especially the relative Fisher information measures, are particularly useful. Using this, we can rationalize why the G3 form of the relative Fisher information, which measures the deviation of effective nuclear charge between an atom-in-a-molecule and the reference pro-atom, is especially effective as a predictor of molecular polarizability. Methods: There are no methods used in this paper, which relies on mathematical derivation and analysis. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEAs) are promising candidates for the electrocatalyst of hydrogen evolution reaction (HER) due to their unique properties such as cocktail electronic effect and lattice distortion effect. Herein, the ultrasmall (sub-2 nm) nanoparticles of PtRuCoNiCu HEA with uniform element distribution are highly dispersed on hierarchical N-doped carbon nanocages (hNCNC) via low-temperature thermal reduction, denoted as us-HEA/hNCNC. The optimal us-HEA/hNCNC exhibits excellent HER performance in 0.5 M H2SO4 solution, achieving an ultralow overpotential of 19 mV at 10 mA·cm−2 (without iR-compensation), high mass activity of 13.1 A·mgnoble metals−1 at −0.10 V and superb stability with a slight overpotential increase of 3 mV after 20,000 cycles of cyclic voltammetry scans, much superior to the commercial Pt/C (20 wt.%). The combined experimental and theoretical studies reveal that the Pt&Ru serve as the main active sites for HER and the CoNiCu species modify the electron density of active sites to facilitate the H* adsorption and achieve an optimum M-H binding energy. The hierarchical pore structure and N-doping of hNCNC support also play a crucial role in the enhancement of HER activity and stability. This study demonstrates an effective strategy to greatly improve the HER performance of noble metals by developing the HEAs on the unique hNCNC support. [ABSTRACT FROM AUTHOR]

An experimental study was conducted to test the effect of changing the frequency of a 10 kV alternating voltage source on the properties of a plasma jet. Optical emission spectra of the plasma were recorded and analyzed. In plasma physics, the electron temperature and density are key parameters. These were determined using a Boltzmann plot and the Stark broadening of the argon line at 763.153 nm, respectively. As the frequency of the alternating voltage source was increased from 10 to 30 kHz (in increments of 5 kHz), the electron temperature increased from 0.995 to 1.357 eV and the electron density rose from 12.027 × 1017 to 12.838 × 1017 cm−3. A strong correlation between the plasma parameters and the frequency of the alternating voltage source was evident. Measurements were also taken on the length of the plasma torch, which was found to grow from 0.041 to 0.051 m as the frequency of the supply voltages was increased. Furthermore, the effect of plasma on the temperature of a silicon target was investigated for a range of frequencies of the supply voltage. It was observed that a slight increase in temperature occurred with increasing frequency, at a constant argon gas flow rate. The effect of plasma jetting on a silicon target was studied at a fixed voltage frequency and a variable gas flow rate. Only a small increase in target temperature was observed. This ensures that no damage or unwanted effects occur on the material being processed. [ABSTRACT FROM AUTHOR]

Copper selenide (Cu2Se) has attracted extensive research interest in the field of thermoelectricity due to its large abundance of constituent elements, environmental friendliness, and excellent thermoelectric properties. In this study, a facile and low-cost hydrothermal synthesis method combined with vacuum sintering was used for Cu2Se-based sample preparation, and the possibility of improving the thermoelectric properties of Cu2Se by doping with rare earth elements (Tm, Er, Lu) was explored using experimental tests and density functional theory calculations. The electronic structure calculations show that the electrical conductivity is increased due to the increased electron density after rare earth element doping. At the same time, the sharp increase in the density of states at the Fermi level after rare earth element doping enhances the Seebeck coefficient of the Cu2Se matrix. The experimental results show that the thermoelectric properties of all the samples doped with rare earth elements (Tm, Er, Lu) were improved compared to the Cu2Se matrix. The doping of rare earth elements led to an increase in point defects and the formation of pores in the samples, which play an important role in reducing the thermal conductivity. Among them, the Tm-doped Cu1.995Tm0.005Se sample reached a maximum ZT value of 0.80 at 773 K, which is a nearly 43% increase compared to the Cu2Se matrix (ZTmax = 0.56). [ABSTRACT FROM AUTHOR]

The two-dimensional electron gas (2DEG) at the LaAlO /SrTiO (LAO/STO) interface exhibits gate-tunable superconductivity with a dome-like shape of critical temperature as a function of electron concentration. This behavior has not been unambiguously explained yet. Here, we develop a microscopic model based on the Schrödinger–Poisson approach to determine the electronic structure of the LAO/STO 2DEG, which we then apply to study the principal characteristics of the superconducting phase within the real-space pairing mean-field approach. For the electron concentrations reported in the experiment, we successfully reproduce the dome-like shape of the superconducting gap. According to our analysis such behavior results from the interplay between the Fermi surface topology and the gap symmetry, with the dominant extended s-wave contribution. Similarly as in the experimental report, we observe a bifurcation effect in the superconducting gap dependence on the electron density when the 2DEG is electrostatically doped either with the top gate or the bottom gate. Our findings explains the dome-shaped phase diagram of the considered heterostucture with good agreement with the experimental data which, in turn, strongly suggest the appearance of the extended s-wave symmetry of the gap in 2DEG at the LAO/STO interface. [ABSTRACT FROM AUTHOR]

Development of new organic synthetic methods fascinating the researchers which facilitating the increasing demands of the modern society, environmental friendly with high efficiency and low cost. The introduction of chromophores in an organic molecules facilitating intersystem crossing (ISC) to harvest both singlet and triplet excitons is also currently demanding field. We report a facile synthesis of symmetrical azines from carbonyl compounds and hydrazine hydrate with carboxylic acid esters as catalyst in methanol. This reaction presents a condensation of primary amino groups in hydrazine hydrate and carbonyl compounds took place simultaneously in a very short refluxing time. The prepared azines 1–10 were structurally analysed by various analytical techniques such as LC-MS1, H NMR13, C NMR, UV-Vis, FTIR and single crystal X-ray diffraction. Photoluminescence properties of prepared azines were recorded in CCl4 at 1 × 10−3 M and excitation range from 329 to 362 nm. The photoluminescence analysis results revealed that compounds 1–10 (except 8) were showed delayed fluorescence and 8 was showed fluorescence property. The photophysical properties of compounds 1–10 such as electron density and band gap energies was calculated by density function theory. This results revealed that the intra-molecular charge transfer occurs within the azines. The azine function in the azines enabling intersystem crossing hence, it is showing phosphorescence. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO) based electrolytes critically govern the security and energy density of solid-state batteries, but typically suffer from poor oxidation resistance at high voltages, which limits the energy density of batteries. Here, we report a Lewis-acid coordinated strategy to significantly improve the cyclic stability of 4.8 V-class PEO-based battery. The introduced Mg2+ and Al3+ with strong electron-withdrawing capability weaken the electron density of ether oxygen (EO) chains via chelation in the coordination structure, resulting in a locally limited interaction between the EO chains and the surface of cathodes at high state of charge. The batteries using Lewis-acid coordinated electrolytes and Ni-rich cathodes achieve high voltage stability of 4.8 V over 300 cycles. Further, the realization of industrial-scale electrolyte membranes, and Ah-level pouch cells over 586 Wh kg‒1 with good cyclic stability, suggests the potential of our strategy in practical applications of all-solid-state batteries. This work reports a Lewis-acid coordinated strategy to improve stability of a 4.8 V-class PEO-based battery. The batteries using Lewis-acid coordinated electrolytes and Ni-rich cathodes achieve high voltage stability of 4.8 V over 300 cycles. [ABSTRACT FROM AUTHOR]

The self-consistent field (SCF) generation of the three-dimensional (3D) electron density distribution (ρ) represents a fundamental aspect of density functional theory (DFT) and related first-principles calculations, and how one can shorten or bypass the SCF loop represents a critical question in electronic structure theory from both practical and fundamental standpoints. Herein, a machine learning strategy, DeepSCF, is presented in which the map between the SCF ρ and the initial guess density (ρ0) constructed by the summation of neutral atomic densities is learned using 3D convolutional neural networks (CNNs). High accuracy and transferability of DeepSCF are achieved by first encoding ρ0 on a 3D grid and then expanding the input features to include atomic fingerprints beyond ρ0. The prediction of the residual density (δρ) rather than ρ itself is targeted, and given that δρ is indicative of chemical bonding information, a dataset of small-sized organic molecules featuring diverse bonding characters is adopted. The fidelity of DeepSCF is finally enhanced by subjecting the atomic geometries of the dataset to random rotations and strains. The effectiveness of DeepSCF is demonstrated using a complex carbon nanotube-based DNA sequencer model. This work evidences that the nearsightedness in electronic structure can be optimally represented via the spatial locality in CNNs, offering insight into the success of various machine learning-based atomistic materials simulations. [ABSTRACT FROM AUTHOR]

Features of the generation of a highly ionized plasma from a tip cathode after the electrical breakdown of a millimeter air discharge gap at atmospheric pressure have been studied using picosecond laser probing at a wavelength of 532 nm. It has been found that the transformation of a micron-sized cathode spot to a growing spark channel is accompanied by the formation of a spherical plasma region in the base of the spark channel in the near-cathode region. The electron density in this region, which is about 100 μm in diameter, decreases to 3 × 1019 cm–3 in the center and increases to (5–6) × 1019 cm–3 in its shell with a thickness of about 20 μm. It has been shown that the growth of the subsequent spark channel is governed by a strong ionization front formed at the boundary of the expanding spherical plasma region in 1 ns after the gap breakdown. It has been assumed that the formation of the spherical plasma region in the near-cathode region affects the subsequent development of the microstructure of the electric spark. [ABSTRACT FROM AUTHOR]

Expressions are derived for the relationship between the metallicity index m with the ratio of the absolute value of the potential electron energy density (V) to the kinetic energy density (G) at the bond critical point (BCP) using the quantum theory of atoms in molecules (QTAIM) and the electron localization function (ELF) value at the BCP. It is found that the ELF maximum (ELFBCP = 1) is achieved at . It is shown that calculated values should not exist in a range . The values are calculated and analyzed for some simple molecules and crystals. [ABSTRACT FROM AUTHOR]

A layered compound of molybdenum disulfide with cationic molecules of the medication lamivudine (Lam) is prepared by the monolayer dispersion method. The structure of this compound is determined by modeling the powder XRD pattern using the supercell method followed by a quantum chemical optimization of the obtained structural model using the electron density functional method. The AIM (Atoms in Molecules) topological analysis of the calculated electron density distribution reveals interatomic bonding interactions between Lam and MoS2 monolayers. The energies of these interactions are estimated. It is shown that the interaction is mainly due to the NH⋯S hydrogen bonds between Lam and the sulfide layer and that these bonds determine the position of molecules in the MoS2 interlayer The features of bonding between Lam and the surface of MoS2 monolayer particles are determined using a computational model of exfoliated compound. [ABSTRACT FROM AUTHOR]

This study explores open-shell biradical and polyradical molecular compounds based on extended multireference (MR) methods (MR-configuration interaction with singles and doubles (CISD) and MR-averaged quadratic coupled cluster (AQCC) approach) using the numbers of unpaired densities NU. These results were used to guide the analysis of the fractional occupation number weighted density (FOD) calculated within the finite temperature (FT) density functional theory (DFT) approach. As critical test examples, the dissociation of carbon–carbon (CC) single, double and triple bonds and a benchmark set of polycyclic aromatic hydrocarbons (PAHs) have been chosen. By examining single, double, and triple bond dissociations, we demonstrate the utility and accuracy but also limitations of the FOD analysis for describing these dissociation processes. In significant extension of previous work (Phys Chem Chem Phys 25: 27380–27393), the assessment of FOD applications for different classes of DFT functionals was performed examining the range-separated functionals ωB97XD, ωB97M-V, CAM-B3LYP, LC-ωPBE, and MN12-SX, the hybrid (M06-2X) functional and the double hybrid (B2P-LYP) functional. In all cases, strong correlations between NFOD and NU values are found. The major task was to develop a new linear regression formula for range-separated functionals allowing a convenient determination of the optimal electronic temperature Tel for the FT-DFT calculation. We also established an optimal temperature for the semiempirical extended tight-binding GFN2-xTB method. These findings significantly broaden the applicability of FOD analysis across various DFT functionals and semiempirical methods. [ABSTRACT FROM AUTHOR]

Accurate determination of the ionospheric parameters is one of the important objectives of the Ionospheric Connection Explorer (ICON) mission. Recent analyses of the current ICON Level 2.5 (L2.5) data product have shown that the ionospheric parameters (e.g., the peak electron density, n m F 2 , and the peak height, h m F 2 ) that are retrieved from the nighttime OI 135.6 nm emission observed by ICON's Far Ultraviolet (FUV) imager exhibit a systematic bias when compared to external radio measurements. In this study, we demonstrate that the bias was introduced by Tikhonov regularization that was used for the FUV Level 1 data inversion to generate the L2.5 data product. To address the bias, we develop a Bayesian framework for accurate determination of the nighttime ionospheric parameters through the Maximum A Posteriori (MAP) estimation. We show through analysis of synthetic observations that the key to an accurate MAP estimation is to construct a series of prior distributions associated with different h m F 2 using climatological empirical models. Implementation of the MAP estimation with this series of prior distributions to the ICON FUV observations and comparison of the ionospheric retrievals with external radio measurements verify that the Bayesian method can reduce the systematic bias to a negligible level of ∼1% in the retrieved n m F 2 and ∼1 km in the retrieved h m F 2 . Our study provides a novel method for FUV remote sensing data analysis and an improved data set for ionospheric research. [ABSTRACT FROM AUTHOR]

Context: 1,1- and 1,2-ethenedithiol are elusive systems that could potentially exist in interstellar space, similar to analogous diols. In this paper, we investigate the structure, stability, and bonding characteristics of these compounds as well as the ions produced by protonation, deprotonation, or simple ionization processes. 1,2-ethenedithiol has two isomers, Z and E, with the most stable conformer being syn-anti for the Z isomer and anti-anti for the E isomer. However, the energy gaps between the different conformers are never larger than 6 kJ·mol−1. For 1,1-ethenedithiol, the global minimum is the syn-anti conformer. The vertical and adiabatic ionization processes as well as the intrinsic basicities and acidities of these families of compounds were analyzed and compared with those of the corresponding diols previously reported in the literature. This comparison revealed not only the numerical differences in these thermodynamic properties but also distinct trends between the two families of compounds. Methods: State-of-the-art G4 ab initio calculations were employed to calculate the structures and total energies of the systems under investigation. The QTAIM, ELF, and NBO approaches were used to analyze the electron density of all the neutral and charged systems included in our study. Van der Waals contributions, when relevant, were analyzed by locating regions of low reduced density gradient(s) using the NCIPLOT approach. [ABSTRACT FROM AUTHOR]

Context: The intermolecular interactions of ethyl acetate (EtOAc)-water (H2O)/ethanol (EtOH) mixtures were investigated using a combination of Raman spectroscopy and quantum chemical calculations. The computational approach was used to analyze the structure of hydrogen-bonded complexes of ethyl acetate with water/ethanol molecules, based on density functional theory (DFT). The calculated frequencies closely matched the experimental Raman values, with differences being under 4%. Experimental data show that when the concentrations of ethyl acetate in the ethyl acetate/water/ethanol solutions were reduced, almost all Raman spectral bands are blue-shifted. The AIM analysis reveals that all the given complexes possess a positive energy density, indicating that the molecules interact electrostatically. The energy and bond length indicate that the methyl group forms relatively weak hydrogen bonds. Analysis indicates that EtOAc forms weak H-bonding C = O∙∙∙H and C-H∙∙∙O, which are recognized as van der Waals interactions. As the amount of ethyl acetate decreases in the complex, the interaction forces also decrease. This could also explain why the bands are blue-shifted. It was discovered that the title complexes' hydrogen bond energy decreased exponentially as bond length increased. Methods: The geometries of the molecular complexes were optimized using the Gaussian 09W program and the B3LYP/6–311 + + G(d,p) set of functions. The potential energy distribution (PED) analysis was performed using VEDA 4.0 software. Raman spectra were drawn using the Origin 8.5 software. The Multiwfn 3.8 software was used to calculate topological parameters of electron density in molecular systems. GaussView 6.0 and Visual Molecular Dynamics (VMD) 1.9.3 tools were used to visualize all computational results. [ABSTRACT FROM AUTHOR]

Context: The theory of reactivity based on cDFT has been supplemented with the new method of calculating the atomic and local indices. With the use of previously derived relationship of the electron density gradient to the softness kernel and to the linear response function, we deliver theoretical analysis to obtain significant reactivity indices—the electron density derivatives: local softness and local hypersoftness together with the global hyperhardness index and the derivative of the global softness with respect to the number of electrons. The local derivatives have been applied in the calculation of responses of atoms to perturbation by an external potential by the alchemical approach. The vital role of the local softness has been confirmed; the potential role of the hypersoftness has been indicated. Method: Our original theoretical scheme has been numerically illustrated with the results obtained with electron density calculations with B3LYP method implemented in Gaussian 16 package. The aug-cc-pvqz basis set has been routinely applied, except for the Ca atom (cc-pvqz). Using the pVTZ basis set recommended by Sadlej was necessary for the potassium atom. [ABSTRACT FROM AUTHOR]

This prefatory review begins with historical background relating to the emergence of the electrostatic potential into the field of chemistry and related fields, leading then into the major focus of this paper: electrostatic potentials at nuclei. The electrostatic potential at the nucleus of an atom, whether it be in the free state or in a neutral molecule or in an ionic molecular species, is qualitatively a characteristic property of the atom. It changes remarkably little from one molecular environment to another. As has been shown earlier by Politzer, the energies of atoms and molecules can be expressed both approximately and rigorously in terms of the electrostatic potentials at their nuclei. For example, molecular energies can be written entirely as summations over atomic contributions, with no explicit interatomic terms. This provides a basis for estimating the energy of an atom in a molecule and supports the validity of the atoms-in-molecules concept, however without the necessity of boundaries for the atoms. This has been further substantiated by a recent paper entitled "Atoms do exist in molecules: Analysis using electrostatic potentials at nuclei", where the authors have shown that the electrostatic potential created by the electrons of all the other atoms at a particular nucleus in a molecular species, not including those associated with that particular atom itself, is almost identical in magnitude to the potential due to the other nuclei. The significance of this will be discussed, with an emphasis on atoms in molecules without boundaries. [ABSTRACT FROM AUTHOR]

The adsorption attributes of methyl naphthalene and naphthalene molecules on P-Germanane sheets are explored based on the density functional theory method. The novel P-Germanane stability is established based on formation energy and phonon band spectrum. The stable P-Germanane exhibits a band gap of 3.944 eV. The calculated adsorption energy infers that methyl naphthalene and naphthalene are physisorbed on P-Germanane sheets. The charge transfer reveals that P-Germanane sheets behave as donors of electrons and target molecules behave as acceptors. The electronic attributes of P-Germanane sheets get altered owing to methyl naphthalene and naphthalene adsorption inferred from the band structure, PDOS spectrum, and electron density difference diagrams. We identified global minima position upon adsorption of 1-methylnaphthalene, and naphthalene on P-Germanane, which are named as bridge, octal, and tetra sites and adsorption attributes are explored in these sites. The adsorption energy and relative energy gap variation are noticed to be maximum for tetra site orientation of naphthalene on P-Germanane. The outcome exposes that P-Germanane sheets can be used as adsorption substrates for the detection of methyl naphthalene and naphthalene molecules. [ABSTRACT FROM AUTHOR]

Quantum Hall systems are platforms of choice to study topological properties of condensed matter systems and anyonic exchange statistics. In this work we have developed a tunable radiofrequency edge magnetoplasmonic resonator controlled by both the magnetic field and a set of electrostatic gates, meant to serve as a versatile platform for future interferometric devices designed to evidence non-abelian anyons. In our device, gates allow us to change both the size of the resonant cavity and the electronic density of the two-dimensional electron gas. We show that we can continuously control the frequency response of our resonator, making it possible to develop an edge magnetoplasmon interferometer. As we reach smaller sizes of our resonator, finite size effects caused by the measurement probes manifest. In the future, such device will be a valuable tool to investigate the properties of non-abelian anyons in the fractional quantum Hall regime. Edge-magnetoplasmon interferometers have been proposed as a tool to investigate anyonic properties of quasiparticles in the regime of the Fractional Quantum Hall effect. In this work, the authors demonstrate the possibility to control electrostatically the resonance frequency of EMP resonators of micrometric size and explain the role of gates, paving the way toward the realization of anyonic interferometers. [ABSTRACT FROM AUTHOR]

Titanium diselenide (TiSe2) is a layered material that under a critical temperature of Tc ≈ 200 K features a periodic modulation of the electron density, known as charge density wave (CDW), which finds applications in quantum information and emerging electronic devices. Here, we present first-principles calculations showing the suppression of the CDW via photoexcitation and consequent stabilization of the undistorted high-temperature phase, in agreement with experimental observations. Interestingly, the unfolded CDW melting is accompanied by a sizable reduction in the thermal conductivity, κ, of up to 25% and a large entropy increase of ~10 J K−1 kg−1. The significant κ variation is almost entirely originated from photoinduced changes in the phonon–phonon scattering processes involving a high-symmetry soft phonon mode. Our results open new possibilities in the design of devices for thermal management and phonon-based logic, and suggest original applications in the of context solid-state cooling. [ABSTRACT FROM AUTHOR]

In this paper, the laser and arc are shifted laterally to change the position and energy distribution of arc discharge, which provides a new idea and theoretical basis for solving the narrow gap welding defects of titanium alloy thick plate. In this study, the effect of transverse offset distance between laser and arc (DLAP) on the discharge characteristics of hybrid heat source coupling and the flow characteristics of molten pool was studied by using the welding method of plate surfacing. The dynamic behavior of the arc plasma, the molten pool, and the keyhole was monitored in real time, and the plasma spectral information was collected to analyze its energy distribution characteristics. The results show that under different DLAP conditions, the charged plasma of the hybrid heat source has two different states: strong coupling state and separation state. When DLAP = 2 mm, the plasma at the center of the keyhole has the strongest spectral intensity, the lowest electron temperature, and the highest electron density, which are 15174, 9546 K, and 1.88 × 1017/cm3, respectively. At this time, the weld pool and keyhole have the maximum arc pressure and Marangoni force, resulting in an increase in the flow velocity of the weld pool and an increase in the area of the weld pool. [ABSTRACT FROM AUTHOR]

Nanozymes have been attracting widespread interest for the past decade, especially in the field of cancer therapy, due to their intrinsic catalytic activities, strong stability, and ease of synthesis. However, enhancing their catalytic activity in the tumor microenvironment (TME) remains a major challenge. Herein, we manipulate catalytic activities of Ru nanozymes via modulating lattice spacing in Ru nanocrystals supported on nitrogen-doped carbon support, to achieve improvement in multiple enzyme-like activities that can form cascade catalytic reactions to boost cancer cell killing. In addition, the lattice expansion in Ru nanocrystals improve the responsiveness of the nanozymes to self-powered electric field, achieving maximized cancer therapeutic outcome. Under the electrical stimulation provided by a human self-propelled triboelectric device, the Ru-based nanozyme (Ru1000) with a lattice expansion of 5.99% realizes optimal catalytic performance and cancer therapeutic outcome of breast cancer in female tumor-bearing mice. Through theoretical calculations, we uncover that the lattice expansion and electrical stimulation promote the catalytic reaction, simultaneously, by reducing the electron density and shifting the d-band center of Ru active sites. This work provides opportunities for improving the development of nanozymes. Nanozymes are promising for cancer therapy, but it is challenging to enhance the catalytic activity of nanozymes in the tumor microenvironment. Here, the authors report that modulating lattice spacing of ruthenium-based nanozymes improves their catalytic activity and electro-responsiveness to self-powered electric field, optimizing cancer therapeutic outcome. [ABSTRACT FROM AUTHOR]

We report a novel deep learning (DL) method for classifying inorganic compounds using 3D electron density data. We transform Density Functional Theory (DFT)-derived CHGCAR files from the Materials Project (MP) and experimental data from the Inorganic Crystal Structure Database (ICSD) into point clouds and sparse tensors, optimized for use in DL models such as PointNet and Sparse 3D CNN. This approach effectively overcomes the limitations of handling the dense 3D data, a common challenge in DL. Contrasting with traditional 1D or 2D X-ray diffraction (XRD) patterns that necessitate complex reciprocal space analysis, our method utilizes 3D density data for direct interpretation in real lattice space. This shift significantly enhances classification accuracy, outperforming traditional XRD-driven DL methods. We achieve accuracies of 97.28%, 90.77%, and 90.10% for crystal system, extinction group, and space group classifications, respectively. Our 3D electron density-based DL approach not only showcases improved accuracy but also contributes a more intuitive and effective framework for materials discovery. [ABSTRACT FROM AUTHOR]

Lattice oxygen in metal oxides plays an important role in the reaction of diesel oxidation catalysts, but the atomic-level understanding of structural evolution during the catalytic process remains elusive. Here, we develop a Mn2O3/SmMn2O5 catalyst using a non-stoichiometric exsolution method to explore the roles of lattice oxygen in NO oxidation. The enhanced covalency of Mn–O bond and increased electron density at Mn3+ sites, induced by the interface between exsolved Mn2O3 and mullite, lead to the formation of highly active lattice oxygen adjacent to Mn3+ sites. Near-ambient pressure X-ray photoelectron and absorption spectroscopies show that the activated lattice oxygen enables reversible changes in Mn valence states and Mn-O bond covalency during redox cycles, reducing energy barriers for NO oxidation and promoting NO2 desorption via the cooperative Mars-van Krevelen mechanism. Therefore, the Mn2O3/SmMn2O5 exhibits higher NO oxidation activity and better resistance to hydrothermal aging compared to a commercial Pt/Al2O3 catalyst. This work reports on an exsolved Mn2O3/SmMn2O5 diesel oxidation catalyst competitive with current commercial materials in reactivity and hydrothermal aging resistance and further clarifies the catalytic mechanism for lattice oxygen as the reactive center [ABSTRACT FROM AUTHOR]

In the present study, we have designed a new water soluble cobalt(II) based one-dimensional (1D) coordination polymer (CP1) for the detection of trace quantities of phosphate ions in aqueous medium. The synthesized coordination polymer was characterized by various spectroscopic, including UV-vis, FTIR, EPR, X-ray diffraction (s-XRD & p-XRD) and analytical techniques to ascertain its structural composition. We have carried out the DFT studies which revealed that HOMO electron density is concentrated over ion central metal and the nitrate ion whereas the electron density of the LUMO is primarily localized over the ligand moiety and partially distributed on the metal ion. Moreover, Hirshfeld surface analysis were aslo performed to substantiate the stability of crystal lattice through intermolecular interactions. We have further examined the sensing activity of the CP1 polymer for the detection of various hazardous inorganic pollutants. Interestingly, a distinctive response by CP1 was noticed in presence of phosphate ions as was substantiated from observing remarkable changes in the electronic and luminescent spectra of the polymer, thereby allowing the quantitative/qualitative detection of phosphate ions even at very lower concentrations. [ABSTRACT FROM AUTHOR]

Molecular and electronic structures of heterobimetallic Ln(III)–Cu(II) C5-symmetric metallamacrocycles (15-metallacrowns-5) bearing L-α-alaninehydroximate (Alaha) ligands are studied by density functional theory (DFT). Full structural DFT optimizations are performed for complexes of the composition {Ln(H2O)4[15-MCCu(II)Alaha-5]}3+ (Ln = La, Ce, Pr) in high- and low-spin states using the PBE functional in the scalar-relativistic approximation. The spin states modeled are: sextet, quartet, and doublet for the La(III)–Cu(II) complex; septet, quintet, triplet, and open-shell singlet for the Ce(III)–Cu(II) complex; octet, sextet, quartet, and doublet for the Pr(III)–Cu(II) complex. The involvement of all unpaired electrons in antiferromagnetic interactions substantially decreases the Gibbs free energy of the singlet Ce(III)–Cu(II) complex compared to that of the doublet La(III)–Cu(II) and Pr(III)–Cu(II) derivatives: –4.4 kcal/mol, –2.0 kcal/mol, and –2.2 kcal/mol respectively (at 5 K). Spin density distributions, electron localization functions (ELFs), and the Laplacian of the electron density in 15-MC-5 reveal Oh and D6h types of the f electron density symmetry around the Ce and Pr nuclei respectively. The effect of the 15-MC-5 metallamacrocyclic environment on the outer electron shell of the central diamagnetic ion is exemplified by the La(III)–Cu(II) complex. The topological parameters of the electron density are calculated at (3, –1) bond critical points for metal–ligand interactions using the quantum theory of atoms in molecules (QTAIM). [ABSTRACT FROM AUTHOR]

A molecular dynamics model of a five-component coating based on the TiAlTaSiN system is proposed. A superposition of interatomic potentials is chosen to describe the interaction between the atoms of the system. The superposition includes both the available interatomic potentials and those calculated on the basis of the electron density functional theory. A molecular dynamics simulation is used to analyze the resistance of the developed coating model to thermal and mechanical loading. The influence of the concentration of alloying inclusions and the crystallographic orientation of the grains of this multi-component coating with respect to the applied load on its strength and deformation properties is investigated. A qualitative agreement between the simulation results and the experimental data is demonstrated. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) hollow nanoparticles present significant potential for photocatalytic applications while their straightforward preparation with precise structure control is still challenging. This work reports the approach to preparing tunable hollow TiO2 nanospheres by utilization of spherical polyelectrolyte brushes (SPB) as nanoreactors and templates. During the preparation, the evolution of the structure was characterized by small angle X-ray scattering (SAXS), and in combination with dynamic light scattering and transmission electron microscopy. The formation of TiO2 shell within the brush (SPB@TiO2) is confirmed by the significant increase of the electron density, and its internal structure has been analyzed by fitting SAXS data, which can be influenced by Titanium precursors and ammonia concentration. After calcining SPB@TiO2 in a muffle furnace, hollow TiO2 nanospheres are produced, and their transition to the anatase crystal form is triggered, as confirmed by X-ray diffraction analysis. Utilizing the advantages of their hollow structure, these TiO2 nanospheres exhibit exceptional catalytic degradation efficiency of methylene blue (MB), tetracycline (TC), and 2,4-dichlorophenoxyacetic acid (2,4-D), and also demonstrate excellent recyclability. [ABSTRACT FROM AUTHOR]

Enhancement of the light-absorption response and utilization of the photogenerated carriers represent a robust strategy for the design of high-performance photocatalyst. In this work, grafting CoxP nanoclusters onto S-scheme heterojunction of W18O49/ZnIn2S4 (WO/ZIS-CoxP) with strong response to the ultraviolet–visible–near infrared ray (UV–vis–NIR) region has been achieved, which possesses efficient electron-transfer-channel, and boosts charge-separation and transport kinetics. The as-prepared WO/ZIS-CoxP yields an impressive solar-driven hydrogen production rate of 45 mmol·g−1·h−1. The increased photocatalytic performance is attributed to the synergistic effect of the composite catalyst: (1) The local surface plasmon resonance-induced "hot electron" injection of W18O49 significantly increases the electron density; (2) the engineered S-scheme directional electron transfer promotes charge separation and enhances the reducing capability of photoexcited electrons; and (3) CoxP as electron-trap site for accelerating surface proton reduction reaction. This work provides a platform to impart nonprecious co-catalyst for engineering S-scheme heterojunction, serving a class of efficient solar-driven photocatalyst towards hydrogen production. [ABSTRACT FROM AUTHOR]

We consider the Cauchy problem for the isentropic compressible Euler–Maxwell equations under general pressure laws in a three-dimensional periodic domain. For any smooth initial electron density away from the vacuum and smooth equilibrium-charged ion density, we could construct infinitely many α -Hölder continuous entropy solutions emanating from the same initial data for α < 1 7 . Especially, the electromagnetic field belongs to the Hölder class C 1 , α . Furthermore, we provide a continuous entropy solution satisfying the entropy inequality strictly. The proof relies on the convex integration scheme. Due to the constrain of the Maxwell equations, we propose a method of Mikado potential and construct new building blocks. [ABSTRACT FROM AUTHOR]

C5F10O-Air mixtures have a great potential to replace SF6 in medium-voltage power equipment. However, during the partial overheating or arc discharge, C5F10O-Air mixtures are inevitably to decompose to form various byproducts. The local chemical non-equilibrium and local thermal non-equilibrium appears due to the finite reaction rates and insufficient energy change between species. This paper establishes a chemical kinetic model to calculate the decomposition byproducts of C5F10O-Air mixtures from 500 K to 3500 K by taking into account the local thermal non-equilibrium and local chemical non-equilibrium simultaneously. The chemical kinetic model contains 50 species and 249 reactions. All the reactions are assumed to be reversible except the reactions producing photos. The local thermal non-equilibrium is characterized by the difference of the electron temperature (Te) and the temperature of heavy species (Th). In this work, the ratio of Te to Th is determined to be a function of the electron number density. Therefore, the value varies with electron number density. The temperature dependent decomposition composition of C5F10O-Air mixtures with C5F10O content to be 5%, 10% and 15% are obtained. In order to investigate the effects of Air on the decomposition of C5F10O, the decomposition products of pure C5F10O from 500 K to 3500 K are also investigated. In addition, the main chemical processes in 0.1C5F10O-0.9Air mixture are investigated by capturing the main reaction pathways. The main reaction pathways can help interpret the formation mechanism of the decomposition products. [ABSTRACT FROM AUTHOR]

Using a melt quenching procedure, bario-borate sodium glasses with varying concentrations of manganese ions (60B2O3-20NaF-(20-x)BaO-XMnO, where X = 0 (Mn-0.0) − 0.5 (Mn-0.5%mol%) were created. The impact of manganese ions on the structural, physical, radiation shielding, and dielectric properties of the Mn-X samples was examined. X-ray diffraction measurements confirmed that Mn-X samples were in an amorphous state. The measured density (ρ) slightly decreased upon the addition of MnO. In the low-frequency interval, the dielectric constant (ε′) declined significantly as the frequency increased. As the MnO content rose to 0.2 mol%, the ε′ value was clearly decreased, but, at higher concentrations, it increased. The glass specimen that had been modified by 0.2 MnO had the lowest dielectric constant, making it a suitable option for packing materials. The tan δ of the examined glasses displayed relaxation peaks. The ability of the prepared glasses as γ-ray shields was investigated using Phy-X/PSD software. The linear attenuation coefficient (LAC) of the proposed Mn-X glasses followed the order: Mn-0.0LAC > Mn-0.1LAC > Mn-0.2LAC > Mn-0.3LAC > Mn-0.4LAC > Mn-0.5LAC. The observed LAC trend can be explained by the glasses being less dense as the MnO component rises. The half-value layer (HVL) followed the trend: Mn-0.0HVL < Mn-0.1HVL < Mn-0.2HVL < Mn-0.3HVL < Mn-0.4HVL < Mn-0.5HVL. The tenth-value layer (TVL) has the same trend as the HVL. The effective atomic number (Zeff) and effective electron density (Neff) for all the proposed Mn-X glasses have the same trend. The Mn-0.0 glasses are located at the mid-point or at a suitable point among the commercial concrete materials as γ-ray shields. [ABSTRACT FROM AUTHOR]

The heterojunction construction through the effective combination of two metal sulfides can significantly improve the photocatalytic performance in the visible light region. In order to improve the photocatalytic efficiency of molybdenum disulfide (MoS2), we synthesized a series of CdS/MoS2 (CM) composites using a simple hydrothermal method. Their photocatalytic activities were evaluated by the photocatalytic hydrogen production. The results showed that the photocatalytic hydrogen production rate of CM composites was significantly enhanced after visible light irradiation, which was attributed to the improvement of visible light absorption capacity, efficient separation of photogenerated carriers, strong photocurrent response, and fast charge mobility. What's more, sample CM-3 exhibited the highest photocatalytic hydrogen production efficiency of 2809.4 μmol g−1 h−1 compared to pure MoS2 (0 μmol g−1 h−1) and CdS (81.5 μmol g−1 h−1). Therefore, the successful construction of heterojunction can accumulate much more photogenerated electrons for MoS2, which is favorable to enhance its photocatalytic hydrogen production. This study provides strong evidence that heterojunction construction can obviously improve the photocatalytic activity. [ABSTRACT FROM AUTHOR]

The ground state electron density — obtainable using Kohn-Sham Density Functional Theory (KS-DFT) simulations — contains a wealth of material information, making its prediction via machine learning (ML) models attractive. However, the computational expense of KS-DFT scales cubically with system size which tends to stymie training data generation, making it difficult to develop quantifiably accurate ML models that are applicable across many scales and system configurations. Here, we address this fundamental challenge by employing transfer learning to leverage the multi-scale nature of the training data, while comprehensively sampling system configurations using thermalization. Our ML models are less reliant on heuristics, and being based on Bayesian neural networks, enable uncertainty quantification. We show that our models incur significantly lower data generation costs while allowing confident — and when verifiable, accurate — predictions for a wide variety of bulk systems well beyond training, including systems with defects, different alloy compositions, and at multi-million-atom scales. Moreover, such predictions can be carried out using only modest computational resources. [ABSTRACT FROM AUTHOR]

Doping is a good way for improving ZnO nanoparticles' structural, optical, electrical, and sensing characteristics. In this context, undoped and ZnO: Ga nanopowders have been synthesized by sol-gel method. After annealing for 2 h at 400 °C, X-ray diffraction, photoluminescence and transmission electron microscopy analysis were carried out for analyzing the synthesized nanoparticle samples. Pure ZnO sample is composed of small particles with regular shapes, while agglomerates of smaller particles are observed in Ga-doped ZnO. XRD demonstrates that Ga ions addition results in no change in ZnO structure. A reduction in band gap value from 3.31 to 3.23 eV after gallium doping due to a decrease of electron density and a drop in conduction band was registered, representing a key factor that participates in gas sensing properties amelioration. Sensing tests towards NO2 gas are performed using a homemade instrument in a Teflon test chamber equipped by an LED UV lamp. The Ga dopant and UV light affect the sensing properties by creating more sites for the interaction between gas molecules and the sensing material surface. With rapid response as well as recovery times and high NO2 selectivity and high stability and repeatability, Ga-doped ZnO sensor could be an excellent candidate compared to other materials to detect NO2 gas at low concentrations and at near ambient temperature. [ABSTRACT FROM AUTHOR]

Motivated by the considerable importance of material properties in modern condensed matter physics research, and using techniques of the -electron systems in terms of the electron density needed to obtain the ground-state energy in density functional theory scenarios, we approach the exchange-correlation energy by considering the interelectronic position corrections and corresponding to the spin and the Coulomb correlation effects, respectively, through the electron–electron potential energy. Exploiting such corrections, we get approximate expressions for the exchange and the correlation functional energies which could be interpreted in terms of magnetic and electric dipole potential energies associated with the charge density described by inverse-square potential behaviors. Based on these arguments, we expect that such obtained exchange-correlation functional energy could be considered in the local density approximation functional as an extension to frame such interelectronic effects. [ABSTRACT FROM AUTHOR]

We are concerned with a simplified quantum energy-transport model for bipolar semiconductors, which consists of nonlinear parabolic fourth-order equations for the electron and hole density; degenerate elliptic heat equations for the electron and hole temperature; and Poisson equation for the electric potential. For the periodic boundary value problem in the torus T d , the global existence of weak solutions is proved, based on a time-discretization, an entropy-type estimate, and a fixed-point argument. Furthermore, the semiclassical limit is obtained by using a priori estimates independent of the scaled Planck constant. [ABSTRACT FROM AUTHOR]

Based on a modified numerical model of the ionosphere and plasmasphere developed at the Institute of Solar–Terrestrial Physics (ISTP), Siberian Branch, Russian Academy of Sciences, the altitude profiles of the Ne electron density for the quiet and disturbed states of the thermosphere were calculated for the conditions of January 25, 2009, at a geographical point with the coordinates 52.4° N, 104.3° E (Irkutsk). The disturbed conditions were set by varying the temperature of neutral particles T in the thermosphere. At altitudes below 180 km and above 250 km, with an increase/decrease in T, an increase/decrease in Ne occurs. At altitudes of 180–250 km, the opposite picture is observed: an increase/decrease in T causes a decrease/increase in Ne. The opposite nature of the change in the Ne profile is associated with the influence of the ratio of concentrations of atomic oxygen and molecular nitrogen [O]/[N2] at the altitudes of region F. Quantitative estimates of the change in Ne at different altitudes with changes in the temperature of neutral particles were obtained. It has been established that a change in T by 1 K leads to a change in Ne by 0.2–0.3%. The modeling results are compared with observations of the peak electron density NmF2 obtained on the Irkutsk ionosonde during sudden stratospheric warming in January 2009. [ABSTRACT FROM AUTHOR]

Cherenkov terahertz (THz) surface plasmons (SPs) generation by a relativistic electron beam over the graphene surface, deposited on a SiO 2 substrate, is investigated. The relativistic electron beam tassel produced by SPs produces perturbed linear current density and develops THz SPs via Cherenkov interaction. Electron beam energy from 498.91 to 499.03 KeV is essential for the excitation of THz SPs of 3 to 10 THz. The growth rate of THz SPs depends on the electron beam density and Fermi energy of the graphene surface. The current investigation possesses the potential to be harnessed for the utilization of THz sensors and detectors. [ABSTRACT FROM AUTHOR]

A heterogeneous CoB/Nb2CTx catalyst was successfully prepared by in situ wet reduction of Co metal ions electrostatically adsorbed on the surface of Nb2CTx and applied to the selective hydrogenation of cinnamaldehyde (CAL). The 10 wt% CoB/Nb2CTx catalyst exhibited superior catalytic activity with a CAL conversion of 90.4% and a cinnamyl alcohol (COL) selectivity of 75.4%, while unsupported CoB showed a CAL conversion of only 24%. The characterization results showed that CoB was dispersed on the surface and in the Nb2CTx layers, and CoB/Nb2CTx exposed more effective active sites than CoB alone, leading to higher hydrogenation activities. In addition, the transfer of electrons from B to Co increased the electron density of Co, which rejects the adsorption on the C=C bond. A strong electronic effect existed between the dispersed surface CoB and Nb2CTx, and B contributed electrons to Nb2CTx, resulting in the formation of more electron-deficient B species, which serve as electrophilic sites for C=O adsorption. Moreover, Lewis acid sites on the surface of Nb2CTx were conducive to the adsorption of C=O bonds. The electron-deficient B and the Lewis acid site on the surface of CoB/Nb2CTx promoted the adsorption of C=O, resulting in a high yield of COL from CoB/Nb2CTx. [ABSTRACT FROM AUTHOR]

The intramolecular [3 + 2] cycloaddition (IM32CA) reactions of azides and diazoalkanes leading to fused tricyclic 1,2,3-triazolines and 1-pyrazolines have been studied at the MPWB1K/6-311G(d,p) computational level within the molecular electron density theory (MEDT). The IM32CA reactions of azides are classified as zw- type following non-concerted one-step mechanism with earlier N1-C5 bond formation implied from the bonding evolution theory (BET) study with the Gibbs free activation energies between 26.3–30.0 kcal mol−1 at 298 K in benzene while that of the diazoalkanes are classified as pmr- type with the earlier C3-C5 bond formation and Gibbs free activation energies between 24.7–29.1 kcal mol−1 at 298 K in n-pentane. The influence of substituent effects on these IM32CA reactions is studied. Azide reactions with minimal global electron density transfer (GEDT) are classified as the null electron density flux (NEDF) while that of the diazoalkanes are classified as forward electron density flux (FEDF). QTAIM analysis and ELF study allow revealing the non-covalent interactions at the TSs. [ABSTRACT FROM AUTHOR]

Herein our study, analysis on the adsorption of VX nerve agent on to X12Y12(Al12N12, Al12P12, C12Si12 and Mg12O12) nanocages is done using density functional theory (DFT). All the calculations were performed using DFT/B3LYP-D3/6-31G (d) basis set, to delve into the capability of these nanocages for sensing and adsorption of VX. Various parameters such as adsorption energy (Eads), energies of highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), Fermi energy (EF), work function alteration (%∆Φ), energy gap (Eg), global electron density transfers (GEDT) along with molecular electrostatic potential (MEP) and density of states (DOS) profiles of the isolates and complex were calculated, compared and examined. The findings exhibited O atom of VX to interact with Al, Si and Mg atoms of the respective nanocages, and the nature of interaction was from nearly covalent to van der Waals. Furthermore, the potential for the nanocage to sense the target gas was analyzed by means of Fermi energy (EF), alteration in work function (%∆Φ) and its recovery time (τ). Among the considered nanostructures, Mg12O12 was recorded with the highest adsorption energy of−97.39 kcal/mol, suggesting it to be a promising adsorbent for VX. [ABSTRACT FROM AUTHOR]

Perovskite solar cells having straightforward design, affordable manufacturing process, and good photovoltaic performance are hot topics nowadays. In this study the designing of four small donor molecules (DM-1–DM-4) by replacing the four-sided methoxy groups of DM-R with different thiophene spacer acceptor moieties. The selected DFT basis set B3LYP/6–31 G** (d,p) method has been used for computational analysis to examine developed HTMs. Lower bandgaps (1.74–2.19 eV) were observed for all of the architecture molecules (DM-1-DM-4), compared to the DM-R (3.40 eV) indicating enhanced electron density transfer. When electron pull-out acceptor moieties are selected, all designed molecules (DM-1–DM-4) have high open-circuit voltage (1.84–1.91 V) and deeper HOMO energies (− 5.31– − 4.98 eV). The architecture molecules (DM-1–DM-4) are extremely soluble, as indicated by their large dipole moments (16.42 D–27.97 D), which are projected to make the fabrication of multilayered films. The reorganization energy of the electron shown by DM-3 was 0.0034 eV, While the reorganization energy of the hole examined in DM-2 was 0.0031 it concluded that maximum electron and hole transfer is achieved in the mentioned molecules as compared to other studied molecules. All HTMs (DM-1–DM-4) show better PCEs (21.39–29.38%) and higher FF (0.8803–0.9043) than R (6.72%). This research shows that DM-1–DM-4 molecules are useful building blocks that are proposed as a theoretical method for creating high-performance PSCs. [ABSTRACT FROM AUTHOR]

Nanozymes are next-generation of nanomaterials with enzyme-like activities. In particular, nanozymes with peroxidase (POD)-like activity have been utilized in various fields, including antibacterial, detection, degradation, etc. However, their extensive applications were limited by their low catalytic activity currently. Herein, we have presented a composite nanozyme based on attapulgite (ATP) (Fe-ATP-MoS2 (FAM)), which exhibited enhanced POD-like activity (185.33 U·mg−1), 4.25 times higher than that of Fe-MoS2 (FM) (43.63 U·mg−1). The density functional theory (DFT) calculations indicated that the addition of ATP increased the electron density of metal centers (Mo and Fe). More importantly, Michaelis–Menten kinetics revealed that the introduction of ATP significantly enhanced the binding affinities of substrates through the pores of ATP, forming a highly concentrated substrate microenvironment and thus promoting its POD-like activity. Additionally, from molecular size and kinetic analysis, we proposed that the changes in substrate size before and after oxidation also significantly affected its Michaelis-constant (Km) value. Furthermore, we utilized FAM in the applications of highly effective antibacterial application and sensitive detection of glutathione (GSH). In conclusion, this work provides a novel approach for designing a highly efficient nanozyme based on natural mineral composites. [ABSTRACT FROM AUTHOR]

Electronic interferometers using the chiral, one-dimensional (1D) edge channels of the quantum Hall effect (QHE) can demonstrate a wealth of fundamental phenomena. The recent observation of phase jumps in a Fabry-Pérot (FP) interferometer revealed anyonic quasiparticle exchange statistics in the fractional QHE. When multiple integer edge channels are involved, FP interferometers have exhibited anomalous Aharonov-Bohm (AB) interference frequency doubling, suggesting putative pairing of electrons into 2 e quasiparticles. Here, we use a highly tunable graphene-based QHE FP interferometer to observe the connection between interference phase jumps and AB frequency doubling, unveiling how strong repulsive interaction between edge channels leads to the apparent pairing phenomena. By tuning electron density in-situ from filling factor ν < 2 to ν > 7 , we tune the interaction strength and observe periodic interference phase jumps leading to AB frequency doubling. Our observations demonstrate that the combination of repulsive interaction between the spin-split ν = 2 edge channels and charge quantization is sufficient to explain the frequency doubling, through a near-perfect charge screening between the localized and extended edge channels. Our results show that interferometers are sensitive probes of microscopic interactions and enable future experiments studying correlated electrons in 1D channels using density-tunable graphene. Previous measurements of interferometers based on quantum Hall (QH) edge channels have suggested potential electron pairing effects. Here, the authors investigate the coupling between QH edge channels in graphene Aharonov-Bohm (AB) interferometers, proposing a possible single-particle explanation for the apparent interference phase jumps and AB frequency doubling. [ABSTRACT FROM AUTHOR]

In the last decades, to improve the CAP treatment efficiency, its biological effects in combination with other physical modalities have widely investigated. However, the physical insight into most of supposed synergistic effects remained elusive. In this regard, the synergetic effect of cold plasma and magnetic field has been used for different applications, especially due to considerable synergistic in biological media reactivity. In the present paper, using a 420 mT N42 magnet, the effect of the perpendicular external static magnetic field (SMF) on the cold atmospheric pressure plasma (CAP) characteristics, such as electron temperature and density, is investigated based on the optical emission spectroscopy, utilizing the Boltzmann plot method, Saha-Boltzmann equation, and Specair software simulation. Results showed that the rotational and electronic excitational temperatures experienced 100 K and 550 K increases in the presence of SMF, respectively. In contrast, the vibrational and translational temperatures remained constant. Moreover, electron temperature was estimated as 1.04 eV in the absence of SMF and increased up to 1.24 eV in the presence of SMF. In addition, the Saha-Boltzmann equation illustrated that the electron density increased in the presence of the additional SMF. The results of the present study indicated that the magnetic field could be an assistant to the cold plasma effect, beneficial in medical applications due to modifications in plasma temperature and electron density. [ABSTRACT FROM AUTHOR]

The evolution of the electronic characteristics of chemical bonds formed and broken along the path of the bimolecular nucleophilic substitution reaction at a tetrahedral central atom, which is the Tt=C, Si, and Ge atom, is analyzed. For this purpose, the reaction paths of the step-by-step replacement of the chlorine atom with the phenyl fragment are modeled, and the energy characteristics of the equilibrium initial, transition, and final states are obtained within the framework of the DFT. For different reaction centers, which are atoms of the carbon group (Tt), changes in electron density distributions and shifts in the positions of the extremes of the total static and electrostatic potential for the forming C–Tt and breaking Tt–Cl bonds along the reaction path are compared. Quantitative criteria are refined that determine the region of existence of a typical noncovalent tetrel bond Tt...Cl, allowing it to be distinguished from a covalent one. Establishment of the properties of the transition state stabilizing tetrel bond may be useful for monitoring the efficient synthesis of covalent organic framework precursors. [ABSTRACT FROM AUTHOR]

This research explores a comprehensive examination of gate underlap incorporated strained channel Cylindrical Gate All Around Nanowire FET having enriched performances above the requirement of the 2 nm technology node of IRDS 2025. The device installs a combination of strain engineering based quantum well barrier system in the channel region with high-k spacers sandwiching the device underlaps and stack high-k gate-oxide. The underlaps are prone to parasitic resistance and various short channel effects (SCEs) hence, are sandwiched by HfO2 based high-k. This SCE degradations and a strong electric field in the drain-channel region is rendered controlling the leakages. The strain based Nanosystem engineering is incorporated with Type-II heterostructure band alignment inducing quantum well barrier mechanism in the ultra-thin cylindrical channel region creating an electrostatic charge centroid leading to energy band bending and splitting among the two-fold and four-fold valleys of the strained Silicon layer. This provides stupendous electron mobility instigating high current density and electron velocity in the channel. Thereby, the device is susceptible to on-current enhancement via ballistic transport of carriers and carrier confinement via succumbing of quantum charge carriers. The device transconductance, Ion, Ioff, Ion/Ioff ratio are measured and the output performance (ID-VDS) characteristics is determined providing emphatic enrichments in contrast to the existing gate all-around FETs as well as the 2 nm technology node data of IRDS 2025. Hence, the strained channel Nanowire FET device developed here is presented here as the device of the future for various digital applications, RF applications and faster switching speed. [ABSTRACT FROM AUTHOR]

The calculation of electron density distribution using density functional theory (DFT) in materials and molecules is central to the study of their quantum and macro-scale properties, yet accurate and efficient calculation remains a long-standing challenge. We introduce ChargE3Net, an E(3)-equivariant graph neural network for predicting electron density in atomic systems. ChargE3Net enables the learning of higher-order equivariant features to achieve high predictive accuracy and model expressivity. We show that ChargE3Net exceeds the performance of prior work on diverse sets of molecules and materials. When trained on the massive dataset of over 100K materials in the Materials Project database, our model is able to capture the complexity and variability in the data, leading to a significant 26.7% reduction in self-consistent iterations when used to initialize DFT calculations on unseen materials. Furthermore, we show that non-self-consistent DFT calculations using our predicted charge densities yield near-DFT performance on electronic and thermodynamic property prediction at a fraction of the computational cost. Further analysis attributes the greater predictive accuracy to improved modeling of systems with high angular variations. These results illuminate a pathway towards a machine learning-accelerated ab initio calculations for materials discovery. [ABSTRACT FROM AUTHOR]