Charge Density Distribution Research Articles

Effects of Sc and Zr on the phase point defects of the three major intermetallic phases in Al-Zn-Mg-Cu alloys from first-principles calculations

Abstract In the Al-Zn-Mg-Cu alloys formed by Laser powder bed fusion( L-PBF ), the elements Sc and Zr are of great importance for the strengthening and toughening properties. The purpose of this study is to investigate the effect of the presence of Sc and Zr on the stability of the phase structure in an Al-Zn-Mg-Cu alloys. First-principles calculations have been used to analyse the influence of Sc and Zr on the mechanical properties of the primary strengthened precipitated phase in Al-Zn-Mg-Cu alloys. The elastic modulus and electronic structure of three main metallic phases containing two types of point defects (Scx, Zrx) have been calculated. Research has demonstrated that the plastic properties of some point defects are improved by the occupation of Sc and Zr elements. Among them, Al2CuMg and MgZn2 are strongly affected by Sc occupation, and Al2Cu are strongly affected by Zr occupation. Zrx-type point defects are more stable than Scx-type point defects in Al2Cu, MgZn2 and Al2CuMg. The charge density distribution near the point defect of Scx and Zrx is higher than the pure phase, and the charges near Scx and Zrx tend to aggregate in a particular direction. In summary, this study reveals the influence mechanism of the intrinsic modification of the main phase point defects of Sc and Zr on the mechanical properties is revealed by the first-principles calculation method, which provides a theoretical basis for the composition design and optimisation of Al-Zn-Mg-Cu alloys with Sc and Zr addition.

High performance triboelectric nanogenerator by synchrotron x-ray assisted Ru/g-C3N4 nanostructure incorporated into PDMS matrix

The integration of metal–semiconductor nanostructures is of significant interest to the advanced technology development. However, the synthesis methods for metal–semiconductor nanostructures are complicated and require multi-stage processing, which includes the separate synthesis of metallic and semiconductor nanostructures, controlling pH, and dedicated equipments. Herein, we report a one-step in situ synthesis and simultaneous embedding of Ru nanostructures on g-C3N4 nanosheets using the synchrotron x-ray irradiation method. The results indicate that Ru nanostructures were uniformly embedded within the g-C3N4 nanosheets, leading to the formation of Ru—O, RuO2, and Ru—O—Ru chemical bonds. Moreover, three distinct types of Ru nanostructures could be achieved by adjusting the x-ray dose. High-performance triboelectric nanogenerators (TENGs) were fabricated using these three types of Ru-embedded g-C3N4 nanosheets within a PDMS matrix. The output performance of these TENG devices was compared with that of PDMS and g-C3N4/PDMS TENGs. The improved dielectric constant contributes to the high performance of the TENG. The synthesized Ru/g-C3N4 nanostructures are notably significant due to increased contact surface area, charge distribution density, and the formation of a metal–semiconductor heterostructure system. These characteristics lead to high charge transfer rates, improved charge transport, and a higher density of charge trapping centers within the insulating matrix. Thus, we achieved a high TENG peak power density of 4.86 W/m2 during the contact separation process. The practical applicability of the TENG is also demonstrated. Furthermore, a 47 μF capacitor could be charged to 7.8 V in ∼400 s and can be used to continuously drive low power electronic gadgets.

Probe on the pivotal role of green rust in improving the enzymatic activity and facilitating the formation of 1O2 in Fenton-like process for degradation of 4-chlorophenol

Iron-based materials have demonstrated significant efficacy in catalyzing hydrogen peroxide (H2O2) for the removal of antibiotics from aquatic environments. Green rust (GR), a hybrid valence state iron-based catalyst, was synthesized. By exploiting the catalytic properties of glucose oxidase (GOx) to generate H2O2 from glucose (Glu), a GR-GOx/Glu system for the removal of recalcitrant organic compound 4-chlorophenol (4-CP) was constructed. In terms of pollutant degradation efficiency, an increase of 30% was observed compared to Fe2+/H2O2 system. Utilizing density functional theory (DFT), we calculated the electrostatic potential energy and charge density distribution, demonstrating the existence of active electron transfer between GR and flavin adenine dinucleotide (FAD), which subsequently enhanced the activity of GOx. The enhancement was pivotal for the sustained generation of preferred oxidative species and rapid degradation of pollutants within the system. Furthermore, the acids and H2O2 generated during enzyme catalysis not only neutralized the alkalinity released by the Fenton-like reaction but also promoted the conversion of superoxide radical (·O2-) to singlet oxygen (1O2). Overall, this study elucidates the fundamental motivation underlying the enhancement of enzymatic activity and highlights the critical role of 1O2 within the system, providing valuable insights into the potential mechanisms by which metal hydroxides catalyze the H2O2 process.

Investigation of the adsorption behavior of Cl and O2 on Al (111) surface based on density functional theory

This study systematically investigates the adsorption behavior of Cl and O2 on the Al surface using first-principle calculations based on density functional theory. The calculation results show that the surface energy of Al on (111) surface is 0.8539J / m2, which is the smallest, indicating that the lowest energy is required for crystal formation on the surface of Al (111). For Cl, the adsorption at the Top site is the most stable, and the adsorption energy is 4.71eV, while the adsorption of O2 at the FCC site is the most stable, and the adsorption energy is 9.92eV. The electronic structure and charge density distribution of Cl and O2 adsorbed on Al (111) surface are also studied. Compared with Cl, the adsorption energy of O2 on Al (111) surface is larger (1.84Å), the length of covalent bond formed is shorter, the number of electron transfer in the adsorption process is more (about 1.79 e), the width of hybrid orbital overlap is wider, and the combination with Al surface is closer. Therefore, the strong adsorption characteristics of O2 in the corrosion process lead to a greater impact on the Al alloy.

Ternary chalcogenides NbInX2 (X = S, Se): A comprehensive investigation of mechanical, electronic, vibrational, optical and thermophysical properties

A comprehensive investigation of the unexplored mechanical, electronic, Mulliken bond population, vibrational, optical and thermophysical properties of the synthesized compounds NbIn[Formula: see text] (X = S, Se) have been made for the first time using the density functional theory. The chemical, mechanical and dynamical stabilities of the compounds are established in our calculations. Both compounds are soft, machinable and brittle. The anisotropic nature of the studied compounds is shown by 3D representations of elastic moduli. The density of states and electronic band structure demonstrate that the compounds are metallic. Fermi surfaces of both compounds are almost similar and contain both hole- and electron-like topologies. The characteristics of chemical bonding among different atoms of the compounds are studied via a charge density distribution map and bond population analysis. Both the compounds possess optical anisotropy. Reflectivity is high (above 44%) in the IR–visible–UV region indicating that the phases may be effective in reducing solar heat. Minimum thermal conductivity, [Formula: see text] (used to select appropriate material for thermal barrier coating) and its anisotropy are calculated for the first time. The results show that both compounds have [Formula: see text] much smaller than the reference value of 1.25[Formula: see text]W[Formula: see text]m[Formula: see text][Formula: see text]K[Formula: see text].

Controlled Heterovalent Vanadium Ion Coordinated Flower-Shaped Supramolecules Cathode for Zinc-Ion Storage.

Vanadium-based materials, which offer multiple oxidation states and rich redox reactions in zinc-ion batteries (ZIBs), have gained substantial attention. However, achieving green and efficient preparation of vanadium oxides-based materials featured with a controlled content of different heterovalent vanadium remains a significant challenge. Herein, a vanadium-supramolecular flower-shaped material (VSF) with heterovalent vanadium was prepared using NH4VO3 as vanadium metal center and hexamethylenetetramine as organic ligand in aqueous solution. The optimal ratio of material (PVSF) after controlling VSF presintering is 2/1 (V5+/V4+). Employing PVSF-2/1 as cathode in ZIBs can achieve a high specific capacity of 398.9 mAh g-1 at 0.2 A g-1, which is increased by 0.2 and 3.5 times as compared with that of pure VO2 and V2O5, respectively. After 2000 cycles, it still delivers a specific capacity of 225 mAh g-1 at 5.0 A g-1. The Zn∥PVSF-2/1 pouch cells were assembled with a satisfactory specific capacity of 339 mAh g-1 at a current of 0.2 A g-1. The excellent performance is ascribed to regulation and coordinated promotion of heterovalent states. The structural pathways corresponding to V5+ act as Zn2+ transport channels to increase Zn2+ transport capability. The V4+ cause high charge density distribution of the V-O lattice layer to provide abundant active sites for the adsorption/desorption process of Zn2+.

Study on Physical Properties of Silicene Nanoribbons Doped As

The paper presents research findings on the structure of armchair silicene nanoribbons doped with arsenic (As) by using density functional theory and the quantum simulation program VASP. The identified electrical and magnetic properties include the electronic band structure, electronic density of states, charge density distribution, spin density distribution, and wave function characteristics. The results indicate that the ASiAsNR structure exhibits metallic properties. Near the Fermi level, contributions from both Si and As are predominant, with Si contributing more near the Fermi level and As contributing more below it. There is a notable electronic density of states around the Fermi level. The findings also show that the σ bonds formed by Si-3s, Si-3px, Si-3py, As-4s, As-4px, and As-4py orbitals are relatively stronger than the π bonds formed by Si-3pz and As-4pz orbitals. Additionally, a distinct correlation is observed between spin-up and spin-down states around the As atoms.

Combined Experimental and Computational Investigations of 4‐Amino‐2‐Chloro‐6,7‐Dimethoxyquinazoline as Potential Anti‐Alzheimer Agent

ABSTRACTAlzheimer's disease (AD) is a neurodegenerative condition that leads to the deterioration of brain cells, resulting in memory loss, thinking, and executive skills. In this work, 4‐amino‐2‐chloro‐6,7‐dimethoxyquinazoline (ACDQ) has been studied using the 6–311++G(d,p) B3LYP functional of the density functional theory (DFT) approach utilizing a basis set. Geometry optimization and fundamental vibrational frequencies are calculated using the above method. The spectroscopic investigations such as FT‐IR, FT‐Raman, and UV–Vis spectra are performed on the selected compound. The time‐dependent DFT calculations are performed in the gas and water phases to determine electronic properties and energy gap using the same basis set. Charge density distributions have been used to illustrate the energy gap between the highest occupied and lowest unoccupied molecular orbitals. Mulliken population analysis is performed to determine the atomic charges of ACDQ. From the natural bond orbital analysis, it is observed that there is a significant electron delocalization in ACDQ due to the presence of intramolecular interactions. To evaluate ACDQ's anti‐Alzheimer potential, a molecular docking simulation is used to assess its structural stability and biological activity against proteins associated with Alzheimer's disease. Our docking study revealed that, ACDQ has a strong interaction with 4EY7 protein with binding energy of −8.1 kcal mol−1. Additionally, metrics such as the root mean square deviation (RMSD), root mean square fluctuation (RMSF), and the radius of gyration are considered (Rg) were computed using molecular dynamics simulations to evaluate the stability of the protein–ligand interaction. Studies on the ADMET prediction of ACDQ have also been carried out. The findings of the current study support the potential of ACDQ as an effective lead therapeutic for Alzheimer's disease.

Desing and In Silico Validation of Vitamin B5 and Its Derivatives As A Potential Target Against Cyclophilin A (CyPA)

The title molecule (N-(2,4-dihydroxy-3,3-dimethylbutyryl)b-alanine), DDBBA and its derivatives were selected for theoretical investigations viz geometry optimization, ADME profiling, binding affinity using quantum-mechanical calculations and modelling simulation tools. Geometry optimization by Gaussian 09 program revealed the stability and electrophilic nature of the investigated molecules. In order to depict the charge density distributions that may be related to biological activity, the contour maps of HOMO-LUMO as well as the associated chemical descriptors such as chemical potential (µ), electronegativity (χ), electrophilicity (ω), hardness (η) and softness (σ) were explored. Utilizing molecular docking, the antiviral, antibacterial, and anticancer activities was examined. The docked molecules showed strong propensity for binding to 2HQ6 cancer protein active sites. Vit B5-CH=CF2 and VitB5-CCl3 showed lowest binding energies (-5.861 and -5.478 kcal/mol) and low inhibition constant values (1.43 M). Studies on the (NBO) natural bond orbital, the Mulliken population, and the Fukui function were all analyzed. Further, the interactions between the derivatives and other molecules were studied using Hirshfeld surface analysis.

Investigation of the Physical Attributes of Sr2GeCrO6, Sr2MgMoO6, Ba2MgMoO6, Ba2ZnMoO6, and Ba2HgWO6 Double Perovskite Oxides

A density functional theory‐based study on the physical properties of significant double perovskite oxides Sr2GeCrO6, Sr2MgMoO6, Ba2MgMoO6, Ba2ZnMoO6, and Ba2HgWO6 has been conducted using the Vienna Ab initio Simulation Package and WIEN2K code. Structural analysis reveals the simple cubic crystal structure of double perovskite oxides. Phonon properties indicate the dynamical stability of Sr2GeCrO6, Ba2MgMoO6, and Ba2ZnMoO6 compounds. The band structure analysis indicates the metallic character of Sr2GeCrO6. However, generalized gradient approximation of Perdew–Burke–Ernzerhof and modified Becke–Johnson both suggest the indirect semiconducting nature of Ba2MgMoO6 and Ba2ZnMoO6. The crystal orbital Hamilton population (–COHP) examination evidences the strongest bonding interactions of O–Ba in these perovskite oxides. Both Ba2MgMoO6 and Ba2ZnMoO6 compounds exhibit p‐type character, as indicated by the partial charge density distributions in the highest occupied molecular orbital and lowest unoccupied molecular orbital (LUMO) orbitals, which govern the band edges near Fermi level. LUMO orbitals are located on Mo and O atoms and are composed of heteronuclear s‐ and p‐type interactions. The investigation comprehensively analyzes calculated optoelectronic properties, including complex dielectric function, optical conductivity, loss function, refractive index, and so on. These parameters are examined in detail, offering profound insights into the materials’ optical and electronic characteristics.

Fabricated S-scheme CoS/CeO2 heterojunction photocatalyst efficiently activates peroxymonosulfate for polyethylene terephthalate plastic degradation: Insight into radicals and electron transfer

Polyethylene terephthalate (PET) plastics are widely utilized, yet they also give rise to significant environmental contamination. In this study, a CoS/CeO2 material with an S-scheme heterojunction was constructed using CoS with CeO2 derived from MOFs and employed for the photocatalytic activation of peroxomonosulfate (PMS) for the degradation of PET. The CoS/CeO2/vis/PMS system demonstrated a degradation rate of up to 95.75 % (weight loss rate) for PET plastic. The performance of this system is much better than that of simple photocatalytic or PMS systems. Photogenerated carriers generated by heterojunctions upon illumination accelerate the fast electron cycling of Co2+/Co3+ through the S-scheme transfer pathway driven by a directional interfacial electric field. This promoted efficient mass transfer in the inhomogeneous phase system (such as SO4•−, e−) and acted as an adsorption activation site for PMS. In-situ X-ray photoelectron spectroscopy (In-situ XPS) and ESR test proved that the electron flow in the heterojunction conforms to the S-scheme mechanism. Density functional theory (DFT) calculations revealed the material of the CoS/CeO2 interface and the successful construction of the modulated electronic structure led to the accumulation of holes on CeO2 and electrons on CoS. Bader analysis on charge density distribution further demonstrated that the formation of the heterojunction decreased the adsorption energy of the PMS on the Co sites, which in turn lowered the energy barrier for the generation of SO4•−. This work would provide a novel solution to the problem of removing plastic pollutants from water, as well as new insight into the construction of S-scheme heterojunctions and the mechanism of photocatalytic PMS activation.

Introducing built-in electric field and spatially separated reactive sites in asymmetric crystalline g-C3N4 for robust photocatalytic hydrogen generation

Constructing arobust internal electric field within photocatalysts is a crucial strategy for propelling the reverse migration of photocarriers and ensuring theeffective occurrence of respective reduction and oxidation reactions. Herein, we synthesized a crystalline g-C3N4 with anasymmetrical structure via introducing a small molecule 2-aminopyrimidine-4,6-diol (AP) and cyano groups on heptazine ring units. The optimized sample (ACNM-3) is endowed with an uneven distribution of charge density and a large dipole moment, thus forming a built-in electric field, which is beneficial for charge separation and migration in space. In-situ XPS and DFT theoretical calculations demonstrate that Pt acts as the reduction site loaded on the inserted AP and the C site of its adjacent heptazine ring, while the oxidation sites are around the heptazine rings containing the cyano groups and the N sites of its adjacent heptazine rings. Such spatially separated redox sites enable ACNM-3 to continuously and robustly trigger proton reduction and TEOA oxidation reactions. Thus, ACNM-3 exhibits an outstanding and stable photocatalytic H2 production rate ofup to 14.19 mmol/g/h, which is over 16 times that of bulk g-C3N4. This work provides a synergistic strategy of internal electric field and catalytic site modulation to synthesize efficient and robust photocatalysts, illuminating the way for the application of photocatalytic H2 production.

Numerical study on characteristics of spiked electrode electrostatic precipitator

The characteristic of the spiked electrode electrostatic precipitator was numerically studied. The spiked electrode had significant effects on the distribution of electric field and charge density. The electric field and charge density were quite high in the area around the spiked electrode tips while decreased rapidly in other area far from the tips. Complicated electrohydrodynamic flow was observed and strong vortices were formed in the upstream and side areas of the spiked electrode. The gas velocity at the tip of the spiked electrode was as high as 28.1 m/s at the working potential of 45 kV. The working potential was more effective for the removal of large particle. The removal efficiency increased 42.4% for 10 µm particle and 15.2% for 0.25 µm particle as working potential increased from 22.5 kV to 45 kV. Low gas velocity was beneficial to the removal of all size particles. The removal efficiency increased by 10% to 15% for all size particles when the gas velocity decreased from 1.0 m/s to 0.6 m/s.

Mitigating Mercury Accumulation and Enhancing Methylmercury Degradation in Rice: Insights from Zinc-Mercury Antagonism at Molecular Levels.

Zn as an essential element has the potential to protect against mercury (Hg) toxicity in rice. However, the antagonistic effects between Zn and Hg in rice and their mechanisms remain unknown. This study proposed a promising strategy for Zn application to mitigate Hg accumulation and toxicity in rice and revealed the underlying molecular mechanisms. The findings revealed that Zn supplementation significantly reduced the uptake and transportation of both IHg and MeHg in rice, thereby alleviating Hg phytotoxicity. In particular, Zn profoundly mitigated Hg-induced oxidative damage to rice, which was attributed to the redistribution of Hg and Zn in the root and Zn competing for binding sites on glutathione. The co-binding of Zn2+ and HgCH3+ within the same active sites of Zn transporters can promote the transfer of regions with a high charge density distribution at the highest occupied molecular orbital (HOMO) level. This process facilitates proton attack on the Hg-C bond, thereby enhancing MeHg demethylation in rice. By elucidating the molecular mechanisms of Zn, IHg, and MeHg interactions in rice, this study offers new insights for developing efficient strategies to mitigate Hg risks while boosting the Zn content in crops, thereby fortifying food safety.

Investigating the electronic properties and reactivity of polyaniline emeraldine base functionalized with metal oxides

Due to its appealing qualities, such as its miniature size and the ability to modify physical properties through chemical synthesis and molecular design, polymer material offers considerable advantages over traditional inorganic material-based electronics. Conjugate polymers are particularly interesting because of their molecular design capabilities, which enable the synthesis of conducting polymers with a variety of ionization potentials and electron affinities (EA), and their ability to control the energy gap and electronegativity (χ). Accordingly, density functional theory (DFT) at the B3LYP/SDD model was used to present possible interactions between polyaniline (PANi) and both alkali and heavy metal oxides. Total dipole moment (TDM), HOMO–LUMO band gap energy (ΔE), ionization energy (IE), EA, chemical hardness (η), chemical potential (μ), electrophilicity index (ω), chemical softness (S), and χ are calculated. TDM of PANi increased while ΔE decreased due to functionalization. The distribution of electronic charge density in molecular electrostatic potential (MESP) maps together with the results of ω reflected the electrophilic nature. The obtained results confirmed that the addition of metal oxides significantly improves the TDM, ΔE, and reactivity descriptors. A strong correlation between the experimental and calculated IR spectra was observed. Additionally, PANi–2MgO and PANi–2MnO model molecules exhibited the highest reactivity. Accordingly, PANi functionalized with MgO and MnO are promising candidates for energy storage devices.

Tuning Electron-Transfer Driving Force in Photosynthetic Special Pair Models.

Visible-light excitation of a family of bimetallic ruthenium polypyridines with the formula [RuII(tpy)(bpy)(-CN)RuII(py)4L]n+ (RuRuLn+), where L=Cl-, NCS-, DMAP and ACN, was used to prepare photoinduced mixed-valence (PI-MV) MLCT states as models of the photosynthetic reaction center. Ultrafast transient absorption spectroscopy allowed to monitor photoinduced IVCT bands between 6000 and 11000 cm-1. Mulliken spin densities resulting from DFT and (TD)DFT computations revealed the modulation of the charge density distribution depending on the ligand substitution pattern. Results are consistent with PI-MV systems ranging from non-degenerate Class II to degenerate Class III or II/III, with electronic couplings between 1000 and 3500 cm-1. These findings guide the control electron localization-delocalization in charge-transfer/charge-separated excited states, like those involved in the photosynthetic reaction center.

Gaussian-Transform for the Dirac Wave Function and its Application to the Multicenter Molecular Integral Over Dirac Wave Functions for Solving the Molecular Matrix Dirac Equation

Gaussian-transform formula is derived for the Dirac wave function. Using it, one can derive the multicenter molecular integral over Dirac wave functions for any physical quantity. As the first application of it, multicenter molecular integrals over Dirac wave functions are derived for the homogeneous charge density distribution model and the Gauss-type charge density distribution model. Such integrals are necessary for solving the gauge-invariant molecular matrix Dirac equation with using the restricted magnetic balance.

Manipulation of ionic transport behavior in smart nanochannels by diffuse bipolar soft layer

Soft bipolar nanochannels provide distinct and valuable understanding of the intricate relationship among shape, charge distribution, concentration, and flow dynamics. This study investigates the intriguing realm of nanoscale structures, where two distinct configurations of soft layers with varying charges provide an intricate but appealing setting for the movement and management of ions, as well as the regulation and control of ionic species in nanochannels with five various geometries. It generates cylindrical, trumpet, dumbbell, hourglass, and conical forms. The nanochannels are coated with a diffuse polyelectrolyte layer, and the charge density distribution in the soft layer is described using the soft step distribution function. To enhance accuracy, the impact of ionic partitioning is taken into account. To investigate the effect of soft layer polarity, two types were considered: Type I and Type II. In Type I, the negative pole is at the start, while in Type II, the positive pole is at the start. Thus, Type I features a bipolar soft layer arrangement of negative–positive (NP), whereas Type II has a positive–negative (PN) configuration. The research was conducted under stationary conditions using the finite element method, Poisson–Nernst–Planck, and Navier–Stokes equations. By manipulating variables such as the arrangement order, charge density of the soft layer, and bulk concentration, a numerical analysis was performed to investigate the impact of these variables on current–voltage parameters. The results demonstrate the soft layer with a positive charge serves as a more effective receiver layer for generating greater rectification. For instance, the dumbbell-shaped nanochannel exhibits a rectification of 2046 at a concentration of 1 mM and the lowest charge density in the soft layer. From an alternative perspective, the conductivity in bipolar nanochannels is significantly influenced by the bulk concentration. The study's findings on the fundamental principles of soft bipolar nanochannels have profound implications for the diverse applications of nanochannels. The capacity to regulate and manipulate ion transport through these nanochannels can result in enhanced efficiency, selectivity, and performance in various processes.

First-principles study of WS2 monolayer decorated with noble metals (Pt, Rh, Ir) as the promising candidates to detect nitrogenous poisonous gases

Rapid identification of nitrogenous toxic gases (NPGs, including NO, NO2, NH3, and HCN) emitted from industrial processes is essential for environmental preservation. In this research, the first-principles calculations have been employed to systematically investigate the adsorption behavior and sensing characteristics of Pt, Rh, Ir-modified WS₂ monolayers (Pt-WS2, Rh-WS2, and Ir-WS2) towards these NPGs, with the aim of assessing the potential of WS2-based gas sensors for NPG detection. The results show that Pt, Rh, and Ir atoms can be stably anchored on the WS2 surface, enhancing its chemical stability and the quantity of active sites. Additionally, the strong orbital hybridization between these noble metal atoms and gas molecules enhances the adsorption capacity of WS₂, markedly boosting the adsorption potency of these modified substances towards NPGs (Eads≥−0.69 eV) while maintaining high selectivity toward NPGs in the presence of interfering gases (H2O, N2, CO2). Analysis of the density of states, charge density distribution, and electron localization function indicates weak chemical adsorption of HCN on Pt-WS2, Rh-WS2, and Ir-WS2, while strong chemical adsorption is observed for NO, NO2, and NH3. Furthermore, the adsorption of NO and NO₂ leads to significant band gap changes (∆Eg > 30 %) of Pt-WS2, Rh-WS2, and Ir-WS2, and the response of work function to NH₃ and HCN adsorption is similarly pronounced (∆Φ > 15 %). Finally, analysis of recovery time indicates that Pt-WS2 and Rh-WS2 can serve as work function gas sensors for HCN and as adsorbents for NO, NO2, and NH3 at room temperature, whereas Ir-WS2 can function as a reusable gas sensor for the effective detection of HCN at high temperature. This investigation establishes a robust theoretical framework for the development and manufacture of high-performance WS₂-based gas sensors.

Elastic constants from charge density distribution in FCC high-entropy alloys using CNN and DFT

While high-entropy alloys (HEAs) present exponentially large compositional space for alloy design, they also create enormous computational challenges to trace the compositional space, especially for the inherently expensive density functional theory calculations (DFT). Recent works have integrated machine learning into DFT to overcome these challenges. However, often these models require an intensive search of appropriate physics-based descriptors. In this paper, we employ a 3D convolutional neural network over just one descriptor, i.e., the charge density derived from DFT, to simplify and bypass the hunt for the descriptors. We show that the elastic constants of face-centered cubic multi-elemental alloys in the Ni–Cu–Au–Pd–Pt system can be predicted from charge density. In addition, using our recent PREDICT approach, we show that the model can be trained only on the charge densities of simpler binary and ternary alloys to effectively predict elastic constants in complex multi-elemental alloys, thereby further enabling easier property-tracing in the large compositional space of HEAs.