Atomic Density Research Articles

Atomic-scale insights into precipitates and their interfacial properties in CuCrZr alloys induced by cryogenic treatment

In this study, high-resolution TEM was utilized to provide a detailed characterization of the precipitates in CuCrZr alloys induced by cryogenic treatment. Building on these findings, first-principles computational models were developed to investigate the mechanical properties of various precipitates and their interfacial bonding characteristics with the matrix. The results demonstrated that cryogenic treatment generated two submicron-sized secondary phases in the matrix: pure Cr particles with a BCC structure and Cu5Zr particles with an FCC structure. Additionally, we observed that nano-sized pure Cr particles were dispersed throughout the matrix and exhibited an orientation relationship of (−111) Cu//(0–11) Cr and [0–11] Cu//[−1−1-1] Cr. First-principles calculations revealed that all the above precipitates exhibited higher modulus and hardness compared to the matrix, with Cr particles being particularly notable. Additionally, the adhesion strength of the Cr/Cu interface was exceptional, surpassing that of the fully coherent CuSlab and CuTwin. Furthermore, the analysis of the electronic properties of the interface revealed that the strengthening effect could be attributed to the higher charge density and localized nature of the Cr atoms near the interface. In summary, precipitates with high hardness and strong adhesion to the matrix can more effectively hinder dislocation movement, which is crucial for enhancing the mechanical properties of the alloys.

Nearly close-packed atomic arrangements in BaTi2O5 glass

Recent advancements in glass synthesis have led to the creation of novel oxide glasses without tetrahedral corner-sharing networks. Of particular interest are glasses with high atomic packing densities, showcasing improved functionalities. Conventional analyses revealed the presence of not only four-coordinated polyhedra but also five- or six-coordinated polyhedra, which are connected via corner-sharing, edge-sharing, or face-sharing linkages. This study adapted the reduced atomic arrangement (RAA) method to analyze densely packed oxide glasses. The RAA method revealed a near-close-packed structure within a 10 Å range throughout BaTi2O5 glass, with Ba2+ and O2− ions arranged accordingly. Moreover, the structural model derived from relaxing the closest-packed arrangement via molecular dynamics simulations faithfully replicated the X-ray diffraction data. These findings suggest that minor deviations from the closest-packed atomic arrangement can initiate glass formation without corner-sharing tetrahedral networks. The RAA method proves highly effective in understanding glass formation mechanisms in unconventional oxide glasses.

Exploring the specific chemistries of the cycloaddition reactions of 5‐benzoyl‐3(2H)‐isothiazolone and stable nitrile oxides: Insights from Density Functional Theory analysis

AbstractIsothiazolones are important heterocyclics with pharmacological potency such as anti‐inflammatory, anticancer, antimicrobial, and robust biocidal (used in agrochemicals). This study seeks to provide mechanistic insight into the chemo‐ and regio‐selectivities of the [3 + 2] cycloaddition reaction of 5‐benzoyl‐3(2H)‐isothiazolone (A1) with two stable nitrile oxides, that is, mesitonitrile oxide (A2) and dichlorobenzonitrile oxide (A3) using M06‐2X hybrid density functional calculations coupled with the 6‐311G (d, p) basis sets. Mesitonitrile oxide A2 chemo‐selectively adds across the carbonyl of the benzyl group of A1 while dichloro benzonitrile oxide A3 preferentially adds across the ethylene center of A1. Derivatization of A1 with electron‐donating groups lowers the activation barriers by a very minute margin ranging from 0.1 to 0.5 kcal/mol whereas electron‐withdrawing groups significantly decrease the energetics of the reaction by a margin of 1.1 to 2.5 kcal/mol. Solvation with chloroform does not affect the selectivity of the reaction but tends to increase both activation and reaction energies of the various routes. Analysis of the Parr function on different reactive sites of A1 shows the addition of A2 via the atomic center with the largest Mullikan atomic spin densities. Substitution of the S‐heteroatom with C, O, or N does not affect the regioselectivity of the reaction but lowers the activation energies in the reaction of A1 with A3. The global electron density transfer (GEDT) values predict a polar reaction between A1 and A2 whereas the reaction of A1 and A3 is non‐polar.

Effect of lanthanum oxide on the radiation-shielding, dielectric, and physical properties of lithium zinc phosphate glasses

This study looked at the shielding properties, physical properties, and dielectric spectroscopy of various lanthanum oxide concentrations based on (65-x) P2O5-15 Li2O–15ZnO– 5Bi2O3- xLa2O3 with x = 0.0, 1.0, 2.0, 3.0, and 4.0 mol% glasses. When La2O3 is added, the molar volume quantities fall but the density values increase. The sample with the designation La-4.0 (4.0 mol% La2O3 content) had the highest density observed, 3.2182 g/cm3. Monte Carlo simulations and the Phy-x/PSD software were used to determine the critical gamma radiation attenuation characteristics, particularly linear attenuation coefficients and mass attenuation coefficients of glass samples under investigation. The half-value layer, mean free path, effective atomic number and effective electron density were then examined across a wide energy range (0.015–15 MeV). The findings of the investigation showed that the addition of La2O3 decreased the half-value layer and mean free path while increasing the mass attenuation coefficient, effective atomic number, and effective electron density. The results indicate that the inclusion of La2O3 appears to improve that glass system's ability to deflect gamma and neutron radiation. Over a broad frequency range, the dielectric properties were measured. The dielectric constant (ε′), which is typically steadily decreased with the addition of lanthanum, indicates an increase in the degree of electrical stiffness inside the glass network. Among the samples examined, the glass sample La-4.0 is thought to possess the best properties for electronic packaging due to its maximum propagation speed and lowest dielectric constant.

Multiple Interaction Forces Construct Two‐Dimensional Self‐assembly Kagome Lattices on Au(111)

Comprehensive SummaryKagome lattices have garnered significant attention due to their promising applications in catalysis, electronics, and magnetics. Although many efforts have been paid to the design and synthesis of Kagome lattices, there is a limited focus on constructing this lattice by multiple interaction forces. In this work, we employ 2,7‐dibromo‐carbazole as precursors to successfully fabricate the two‐dimensional self‐assembly Kagome lattices stabled by multiple interaction forces on Au(111) substrate. Using low‐temperature scanning tunneling microscopy, non‐contact atomic force microscopy and density functional theory calculation, we visualize and identify the four interaction forces within Kagome lattices: Au—N coordination bonds, Au—H hydrogen bonds, Br—Br halogen bonds, and Br—H hydrogen bonds, respectively. This study provides a basic understanding for designing and constructing more complex Kagome lattices.

Revealing the mechanism of hydration on the CO2 kinetic adsorption of CaO surface via ReaxFF MD simulations with experiments

Hydration has been regarded as an effective method to improve the cyclic activity of CaO during the Calcium looping CO2 capture process, but its mechanism remains unclear. In this work, the hydration reaction of CaO surface and its underlying mechanism was studied by ReaxFF molecular dynamics simulation combing with TGA experiments. The effect of hydration on the initial CO2 adsorption rate showed a trend of promoting at low H2O degree and inhibiting at high H2O concentration. The CaO surface was easily passivated, and it can maintain its crystal structure and begin to distort at about 1.0 H2O monolayer contents. Hydration failed to promote the CO2 adsorption rate, inversely the CO2 adsorption process accelerated the diffusion of H ions inward the CaO lattice·H2O dissociation produced two hydroxyl groups: direct OwH and indirect OsH. Atomic density profiles showed that the direct hydroxyl pairs were always, and indirect OsH groups can consume surface oxygen active sites, reducing the initial rapid CO2 adsorption activity. On the pre-hydrated CaO surface, CO2 molecules were more likely to bind to solid oxygen active sites than OH groups. The H free radical diffused inside the lattice in the form of transition HO2 state, promoting the slow CO2 adsorption amount.

Comparative study of CF4 + X + He (X = C4F8 or C4H2F6) plasmas for high aspect ratio etching of SiO2 with ACL mask

AbstractThis work compared C4F8 and C4H2F6 gases (as third components in CF4 + He gas mixture) for the high aspect ratio etching of SiO2 through the amorphous carbon layer (ACL) mask. The research scheme included the study of gas‐phase plasma characteristics, etching kinetics, and etching profiles. It was found that CF4 + C4F8 + He and CF4 + C4H2F6 + He gas mixtures are featured by quite close plasma parameters, the kinetics of electron‐impact processes, and ion bombardment intensities. At the same, the use of C4H2F6 provides a bit lower F atom density together with a bit higher polymerizing ability. All these factors cause lower absolute etching rates for both SiO2 and ACL but provide better SiO2/ACL/ACL selectivity and profile features.

A Community Ionosphere‐Thermosphere Observing System Simulation Experiment (OSSE) Tool: Geospace Dynamics Constellation Example

AbstractObserving System Simulation Experiments (OSSEs) provide an effective way to evaluate the impact of assimilating data from a specific observing system on hindcasting, nowcasting, and forecasting of environmental systems. The NSF NCAR's Data Assimilation (DA) Research Testbed/Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (DART/TIEGCM) tool, to be hosted at the NASA Community Coordinated Modeling Center, serves as a valuable and accessible community resource for quantitatively evaluating the impact of observations from both current and future ionosphere‐thermosphere (IT) observing systems. This study demonstrates the utility of DART/TIEGCM as an IT OSSE tool, using synthetic observations simulated using a currently planned NASA Geospace Dynamics Constellation (GDC) observing system design. Five sets of OSSEs are carried out to compare the effects of assimilating various combinations of prospective GDC observations (e.g., neutral temperature, neutral wind, neutral composition, atomic oxygen ion density, and ion and electron temperature) during a major geomagnetic storm period of the St Patrick's Day Storm on 17 March 2013. The maximum error reduction in neutral temperature and atomic ion oxygen density is 24.6% and 43.3% compared to the control experiment. These OSSEs indicate the benefits of coupled IT DA approaches implemented in DART/TIEGCM to maximize the impact of multi‐parameter IT observations, such as those expected from the GDC mission. Although more work is required to draw any definitive conclusion on the GDC data impact, the study provides an illustrative example of how the DART/TIEGCM community tool can be used to evaluate observational impacts of planned or existing missions for geospace research and applications.

MINDS: Mid-infrared atomic and molecular hydrogen lines in the inner disk around a low-mass star

Context. Understanding the physical conditions of circumstellar material around young stars is crucial to star and planet formation studies. In particular, very low-mass stars (M★ < 0.2 M⊙) are interesting sources to characterize as they are known to host a diverse population of rocky planets. Molecular and atomic hydrogen lines can probe the properties of the circumstellar gas. Aims. This work aims to measure the mass accretion rate, the accretion luminosity, and more generally the physical conditions of the warm emitting gas in the inner disk of the very low-mass star 2MASS-J16053215-1933159. We investigate the source mid-infrared spectrum for atomic and molecular hydrogen line emission. Methods. We present the full James Webb Space Telescope (JWST) Mid-InfraRed Instrument (MIRI) Medium Resolution Spectrometer (MRS) spectrum of the protoplanetary disk around the very low-mass star 2MASS-J16053215-1933159 from the MINDS GTO program, previously shown to be abundant in hydrocarbon molecules. We analyzed the atomic and molecular hydrogen lines in this source by fitting one or multiple Gaussian profiles. We then built a rotational diagram for the H2 lines to constrain the rotational temperature and column density of the gas. Finally, we compared the observed atomic line fluxes to predictions from two standard emission models. Results. We identify five molecular hydrogen pure rotational lines and 16 atomic hydrogen recombination lines in the 5–20 µm spectral range. The spectrum indicates optically thin emission for both species. We use the molecular hydrogen lines to constrain the mass and temperature of the warm emitting gas. We derive a total gas mass of only 2.3 × 10−5 MJup and a temperature of 635 K for the warm H2 gas component located in the very inner disk (r < 0.033 au), which only accounts for a small fraction of the upper limit for the disk mass from continuum observations (0.2 MJup). The HI (7−6) recombination line is used to measure the mass accretion rate (4.0 × 10−10 M⊙ yr−1) and luminosity (3.1 × 10−3 L⊙) onto the central source. This line falls close to the HI (11−8) line, however at the spectral resolution of JWST MIRI we managed to measure both separately. Previous studies based on Spitzer have measured the combined flux of both lines to measure accretion rates. HI recombination lines can also be used to derive the physical properties of the gas using atomic recombination models. The model predictions of the atomic line relative intensities constrain the atomic hydrogen density to about 109−1010 cm−3 and temperatures up to 5000 K. Conclusions. The JWST-MIRI MRS observations for the very low-mass star 2MASS-J16053215-1933159 reveal a large number of emission lines, many originating from atomic and molecular hydrogen because we are able to look into the disk warm molecular layer. Their analysis constrains the physical properties of the emitting gas and showcases the potential of JWST to deepen our understanding of the physical and chemical structure of protoplanetary disks.

Observation of highly correlated ultrabright biphotons through increased atomic ensemble density in spontaneous four-wave mixing

The pairing ratio, a crucial metric assessing a biphoton source's ability to generate correlated photon pairs, remains underexplored despite theoretical predictions. This study presents experimental findings on the pairing ratio, utilizing a double-Λ spontaneous four-wave mixing biphoton source in cold atoms. At an optical depth (OD) of 20, we achieved an ultrahigh biphoton generation rate of up to 1.3×107 per second, with a successful pairing ratio of 61%. Increasing the OD to 120 significantly improved the pairing ratio to 89%, while maintaining a consistent biphoton generation rate. This achievement, marked by high generation rates and robust biphoton pairing, holds great promise for advancing efficiency in quantum communication and information processing. Additionally, in a scenario with a lower biphoton generation rate of 5.0×104 per second, we attained an impressive signal-to-background ratio of 241 for the biphoton wavepacket, surpassing the Cauchy-Schwarz criterion by approximately 1.5×104 times. Published by the American Physical Society 2024

Structure‐Guided Engineering of Thermodynamically Enhanced SaCas9 for Improved Gene Suppression

AbstractProteins with multiple domains play pivotal roles in various biological processes, necessitating a thorough understanding of their structural stability and functional interplay. Here, a structure‐guided protein engineering approach is proposed to develop thermostable Cas9 (CRISPR‐associated protein 9) variant for CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) interference applications. By employing thermodynamic analysis, combining distance mapping and molecular dynamics simulations, deletable domains are identified to enhance stability while preserving the DNA recognition function of Cas9. The resulting engineered Cas9, termed small and dead form Cas9, exhibits improved thermostability and maintains target DNA recognition function. Cryo‐electron microscopy analysis reveals structural integrity with reduced atomic density in the deleted domain. Fusion with functional elements enables intracellular delivery and nuclear localization, demonstrating efficient gene suppression in diverse cell types. Direct delivery in the mouse brain shows enhanced knockdown efficiency, highlighting the potential of structure‐guided engineering to develop functional CRISPR systems tailored for specific applications. This study underscores the significance of integrating computational and experimental approaches for protein engineering, offering insights into designing tailored molecular tools for precise biological interventions.

Self-Organizing Sub-μm Surface Structures Stimulated by Microplasma Generated Reactive Species and Short-Pulsed Laser Irradiation.

Catalysts are critical components for chemical reactions in industrial applications. They are able to optimize selectivity, efficiency, and reaction rates, thus enabling more environmentally friendly processes. This work presents a novel approach to catalyst functionalization for the CO2 reduction reaction by combining the reactive species of an atmospheric pressure plasma jet with the electric fields and energy input of a laser. This leads to both a nanoscale structuring as well as a controllable chemical composition of the surface, which are important parameters for optimizing catalyst performance. The treatment is conducted on thin copper layers deposited by high power pulsed magnetron sputtering on silicon wafers. Because atomic oxygen plays a key role in oxidizing copper, two photon absorption fluorescence is used to investigate the atomic oxygen density in the interaction zone of the COST plasma jet and a copper surface. The used atmospheric pressure plasma jet provides an atomic oxygen density at the surface in a distance of 8 mm to the jet nozzle of approximately or a flux of . Pulsed laser-induced dewetting is used to form nanoparticles from the deposited copper layer to enhance catalytic performance. Varying the layer thickness allows control of the size of the particles. A gas flow directed on the sample during the combined treatment disturbs the particle formation. This can be prevented by increasing the laser energy to compensate for the cooling effect of the gas flow. Investigating the surface using X-ray photoemission spectroscopy reveals that the untreated copper layer surface consists mostly of metallic copper and Cu(I) oxide. Irradiating the sample only with the laser did not change the composition. The combination of plasma and laser treatment is able to produce Cu(II) species such as CuO, whose concentration increases with treatment time. The presented process allows the tuning of the ratio of C2O/CuO, which is an interesting parameter for further studies on copper catalyst performance.

Parameter Optimization in Cluster Identification Algorithms for Characterizing Nanoclusters in Al-Mg-Si-Cu Alloys.

Optimization of user-defined parameters (Dmax, Nmin, order (K)) in the Density-based Spatial Clustering of Applications with Noise (DBSCAN) algorithm, used to characterize nanoclusters in Al-0.9% Mg-1.0% Si-0.3% Cu (mass %), was conducted. Ten combinations of parameters with a given K were considered for samples naturally aged (NA) and preaged (PA) at 100°C. We confirmed four types of unphysical clusters, artificially formed, by analyzing composition with size, atomic density, and atomic arrangement inside clusters. The optimum combinations minimizing those unphysical clusters were obtained for both NA and PA samples. Meanwhile, to evaluate the reliability of the optimum combination, volume rendering and isosurfacing were performed. As a result, regions of high solute concentration were confirmed, and those regions are in good agreement with the position of the clusters obtained by applying the optimum combination in DBSCAN. Furthermore, by comparing the optimum combinations with the fixed parameters widely used until now, we showed that for each dataset, considering independent parameters obtained in the same method is desirable rather than using fixed parameters. Consequently, an idea of determining the algorithm parameters for characterizing the nanoclusters in Al-Mg-Si(-Cu) alloys was introduced.

Examining Low-Energy Gamma-Ray Protection of a New Promising Saudi Cement Product as Alternative Cementitious Material Using Geant4 Software

In modern life, cement products have become an essential material for the foundations in many structural building designs. Because of this, the natural effects of this material need to be tested and cannot be ignored. Modeling interactions of gamma rays with several cementitious compounds is the focus of this study. Gamma radiations exist naturally and artificially, but with limited gamma-ray energies, which are not easy to access for experimental gamma attenuation studies. So in the current work, a wide range of low gamma-ray energies (0.01 to 0.356 MeV) are applied to investigate the gamma radiation attenuation properties theoretically for different cement materials. Also, the Monte Carlo statistical method is applied using the Geant4 toolkit to simulate the results. The outcomes are compared with theoretical values using XCOM to validate at these energies. The effective atomic number ( Z eff ), electron density ( N eff ), and half-value layers (HVLs) for the studied samples are computed based on the simulated mass attenuation coefficient ( μ m ), as expected. The outcomes show good agreement between the simulated results with those calculated theoretically by XCOM within an 11% deviation. The silica fume sample showed a slightly higher μ m value compared with the other samples. The dependence of the photon energy and cement composition on the values of the μ m and HVLs are investigated and discussed. In addition, the values of Z eff and N eff for all cement samples behaved similarly in the given photon energy range, and they decreased as the photon energy increased.

Simulating cross‐modal medical images using multi‐task adversarial learning of a deep convolutional neural network

AbstractComputed tomography (CT) and magnetic resonance imaging (MRI) are widely utilized modalities for primary clinical imaging, providing crucial anatomical and pathological information for diagnosis. CT measures X‐ray attenuation, while MRI captures hydrogen atom density in tissues. Despite their distinct imaging physics principles, the signals obtained from both modalities when imaging the same subject can be represented by modality‐specific parameters and common latent variables related to anatomy and pathology. This paper proposes an adversarial learning approach using deep convolutional neural networks to disentangle these factors. This disentanglement allows us to simulate one modality from the other. Experimental results demonstrate our ability to generate synthetic CT images from MRI inputs using the Gold‐atlas dataset, which consists of paired CT‐MRI volumes. Patch‐based learning techniques and a visual Turing test are employed to model discriminator losses. Our approach achieves a mean absolute error of 36.81 4.46 HU, peak signal to noise ratio of 26.12 0.31 dB, and structural similarity measure of 0.9 0.02. Notably, the synthetic CT images accurately represent bones, gaseous cavities, and soft tissue textures, which can be challenging to visualize in MRI. The proposed model operates at an inference compute cost of 430.68 GFlops/voxel. This method can minimize radiation exposure by reducing the need for pre‐operative CT scans, providing an MR‐only alternative in clinical settings.

Role of NiO in wide-bandgap perovskite solar cells based on self-assembled monolayers

NiO/self-assembled monolayer (SAM) double hole transport layers (HTLs) has become the mainstream choice in high-efficiency single-junction and tandem perovskite solar cells (PSCs). However, the underlying role of NiO in double HTLs from the microscale is not systematically revealed currently. Herein, we reveal that NiO plays an important role in inducing a more uniform and thinner SAM from three aspects. Firstly, compared with indium tin oxide (ITO), the NiO surface exposes less crystal facet orientations and a higher metal atom density, suggesting that sufficient chemical binding sites for SAMs are provided to facilitate the close-packed assembly of SAMs. Secondly, NiO modified ITO exhibits smaller surficial roughness and strongly bonded −OH, which is beneficial to the uniform distribution of SAMs and strong adhesion to the NiO surface. Utilizing the well-constructed SAM, we fabricate wide-bandgap (>1.75 eV) PSCs using vacuum-assisted technology and achieve an impressive photoelectric conversion efficiency of 19.55 %. These findings not only deepen the understanding of SAM assembly on substrates but also provide essential guidance for the future industrialization of PSCs.

Gold intercalation of different 6H-SiC(0001) surface reconstructions

We report on in situ investigation of Au intercalation of different zero-layer graphene surface reconstructions of 6H-SiC(0001): (3×3)R30∘+(63×63)R30∘, (63×63)R30∘+(5×5)R0∘, (63×63)R30∘+(5×5)R0∘+Gr. We show that the most appropriate reconstruction for graphene formation via Au intercalation is a one with some fraction of initial graphene monolayer. A well-ordered epitaxial Au(111) islands on the zero-layer graphene were revealed with the same crystallographic orientation as the SiC surface. Ab initio calculations approve that the value of Rashba splitting in graphene increases with the density of Au atoms per unit cell and with the reduction of average distance between Au and graphene.

Reducing the computational complexity of implicit schemes in the modeling of kinetic inelastic collisions in a partially ionized plasma

AbstractModeling the time evolution of atomic number densities and the kinetic (non‐Maxwellian) electron energy distribution function under the action of electron impact collisions by classical approaches requires an implicit time‐stepping scheme to maintain numerical stability. The resulting linear system that must be iteratively solved at each time step incorporates a dense (nonsparse) matrix. For variables being propagated, the computational cost is . We present an alternative approach with a computational cost of , which is the same order as the computational cost of an explicit method for propagating a system of this type. The approach relies on a combination of classical iterative derivative evaluations, combinatorial approximations, and some ideas from deep machine learning.

Impact of La2O3 incorporation on the structural, physical, mechanical properties and radiation shielding performance of basalt glasses

This study investigates the influence of La2O3 addition on the structural, physical, and radiation shielding properties of basalt-based glasses. Incorporating varying concentrations of La2O3 (0, 10, 20, 30 wt%) into basalt glasses, we aimed to evaluate the potential of La2O3 in enhancing the material's effectiveness against gamma radiation. Utilizing Ba-133 point radioactive source and Ultra Ge detector, we measured the attenuation parameters in different photon energies (81, 160, 223, 276, 302, 356, and 383 keV). The glasses exhibited an amorphous structure, as confirmed by XRD analysis, with density values ranging from 2.72 to 3.305 g/cm³, increasing with La2O3 content. The microstructural analysis indicated that La3+ ions predominantly integrate into the glass matrix, enhancing the structural integrity without forming separate phase regions. Our findings demonstrate a significant improvement in radiation protection parameters, including mass attenuation coefficients and half-value layers, with higher La2O3 concentrations. These outcomes were also supported by the data obtained for Zeff and EBF values of G1-G4 glasses. The mechanical properties of the glasses were also investigated with the Makishima-Mackenzie model and it was observed that the elastic moduli were also affected by the addition of La2O3. The enhancements observed with La2O3 additions suggest promising avenues for developing advanced shielding materials, combining the inherent advantages of basalt glasses with the high atomic weight and electron density of lanthanum compounds.

Dissecting of Atomic Morphology of Superfine Pulverized Coal Based on X-ray Pair Distribution Function

Resolving the atomic structure information of the aromatic layers in coal plays a crucial role in understanding the generation mechanisms of NOx during coal combustion and further reducing the formation of NOx from the source. This study reveals the distribution of X-ray diffraction bands of superfine pulverized coal using a high-resolution synchrotron radiation X-ray Diffraction (HRXRD) facility, discussing the distribution of atomic distances and atomic density in aromatic layers through pair distribution function (PDF) methods. Furthermore, the influences of mechanochemistry on the evolution of atomic morphology are focused on. The results show that the PDF of coal gradually stabilizes when r > 8 Å, showing the short-range order of graphite-like structure. Additionally, due to the limitations of scanning angle and X-ray energy, atomic distances in aromatic layers for coal are significantly greater than that of pure graphene. Enhanced mechanochemical effects make the peaks 1, 2, and 3 of coal PDF more similar to graphene's by condensing alkyl side chains into smaller, regular aromatic layers when the particle size decreases. With the enhancement of mechanochemical effects, coals with different metamorphic degrees exhibit different aromatic evolution patterns. The aromaticity of NMG coal first decreases and then increases, while the aromaticity of YQ coal shows the opposite trend. The results can provide deeper insights into the atomic structure of coal macromolecular, which can facilitate the advancement of novel ultra-low NOx combustion methods and support the construction of precise coal macromolecular models.