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In this paper, the thermo-electric, phonon, electronic, and optical properties of the C3N monolayer have been investigated using the Wien2K computational code based on first principles calculations in the framework of the density functional theory. The study of electronic properties shows the behavior of non-magnetic semiconductors with an indirect gap with a value of 0.5 electron volts for this two-dimensional structure. Also, optical properties such as dielectric function, reflection, energy loss function, absorption coefficient, and optical conductivity are calculated. C3N monolayer is optically anisotropic in z and x direction, which according to the refractive index diagram leads to birefringence, which is a key parameter for this compound's linear optical performance. The results provide a fundamental understanding of the design of composite structures used in nanodevices based on two-dimensional advanced materials. The linear response approach along the symmetric points calculates the phonon dispersion diagram. The results indicate the absence of negative modes in the phonon spectrum, indicating that the structure is dynamically stable. Investigating the thermoelectric properties of the C3N monolayer using the semi-classical Boltzmann theory shows that this monolayer has a value coefficient (ZT) close to one at room temperature and temperatures lower than room temperature. As a result, it can be proposed as a candidate for thermoelectric applications.

In this study, the optical and electronic properties of bulk and nano-layer of zinc selenide (ZnSe) and zinc sulfide (ZnS) are investigated. The calculations for solving the many-body Schrodinger equations are performed in the framework of density functional theory using the WIEN2K computational package. The Engel-Vosko and gradient generalized approximation (GGA) treat the exchange-correlation potential. To investigate the electronic and optical properties of zinc selenide and zinc sulfide nano layers, the electronic band structure and the real and imaginary parts of complex dielectric function for the bulk and nano-layer with different thicknesses are calculated and compared. The results of electronic band structures show that the energy band gap of zinc selenide and zinc sulfide nano-layers with various thicknesses decreases to zero and are metal. In contrast, the bulk of zinc selenide and zinc sulfide compounds are semiconductors. The results also show that for each compounds the static dielectric function for the perpendicular and parallel direction to the nano-layer surface is different from the bulk static dielectric function. Comparison between the real parts of complex dielectric function for the bulk and nano-layer shows that absorption of electromagnetic radiation for the ZnSe and ZnS nano-layer in comparison to corresponding bulk results occur in lower energies.

Weyl semimetals show special quantum states of matter, which have nontrivial topological features and very interesting and unique applications in the spintronics industry. One method of making these materials is the use of alloying method. In this paper, the alloys are constructed using the first-principles methods. After study of their stability, their structural, electronic, and topological properties have been studied. To study the structural and electronic properties of the alloys, the Wien2k package, based on density functional theory, has been used. Furthermore, the topological properties of the alloys have been calculated using the Wanniertools packages, based on the tight-binding method. Calculations show that the alloys, in the absence of spin-orbit coupling, have crossing points with fourfold degeneracy and band inversion. Therefore, they are topological Dirac semimetal. Considering the spin-orbit coupling, it is seen that alloys with concentrations of x = 0, 0.25, 0.5, 0.75 change to the normal semimetal by opening the band gap; but, the alloy with x = 1 concentration changes to the topological Weyl semimetal with 16 Weyl fermions couple. The full area of the first Brillouin zone (FBZ) was scanned to find the positions of the Weyl points. The results show that the Weyl points, with chirality of either +1 or -1, were scattered in the FBZ with the central symmetry, but all of them are far from the high-symmetry paths of FBZ. Furthermore, the surface state properties, like Fermi arcs, were calculated and studied for the NbSb Weyl semimetal using the Wanniertools computational packages.

In this paper, the optical properties of GaP in different phases have been investigated. The calculations were performed by using pseudopotential in the framework of density functional theory and using the PWscf code. The pseudopotentials applied here are generated using norm-conserving conditions within GGA for the exchange-correlation function. The optical properties of the Zincblend and Cinnabar phases reveal the conformity between the band structure and the imaginary part of the dielectric function, and the band gap and optical gap are almost equal. The refractive index obtained from the real part of the dielectric function in Zincblend is 3.306 and in the Cinnabar phase is 4.235 and 3.808 in the x and z directions, respectively.

In this research, the effect of hydrostatic pressure on the electronic structure and optical properties of GaAs compound has been investigated. The calculations have been done based on the density functional theory (DFT) using WIEN2K computational package. This computational package solves Kohn-Sham equations by the full-potential linearized augmented plane wave (FP-LAPW) method self-consistently. The exchange-correlation potential is calculated by the Generalized gradient approximation (GGA) and a combination of modified Becke — Johnson plus local-density approximation (mBJ-LDA) functional. All the electronic and optical properties calculations have been done in the presence of spin-orbit interaction. In the case of electronic structure calculations, using the band structure calculations at different pressures, the pressure dependence of band gap energy is calculated. The results of calculations show that by increasing the pressure the band gap energy increases linearly. Regarding the optical properties, the effect of hydrostatic pressure on the real and imaginary parts of the dielectric function ε(ω) is calculated. The results show that by increasing pressure the absorption edge and the major peaks in the imaginary part of the dielectric function are shifted towards higher energies whereas by decreasing the pressure they are shifted towards lower energies. The results also show that by increasing the pressure, the static dielectric function decreases linearly. Using the results of the real and imaginary dielectric function calculations, the optical gap and the static refractive index at different pressures are also calculated.

Given its superior structure, the abundance of surface functional groups, and low cost, cotton fiber filtration paper can be used as the support for hydrogen evolution reaction (HER) and oxygen evolution reaction catalysts (OER) instead of copper foam (CF), nickel foam (NF), or carbon cloth (CC). Herein, the chemical plating method was used to create thin self-supporting electrodes based on cotton fiber filtration paper (FP). The Co-Ni-P amorphous nanospheres can be uniformly dispersed on the self-supporting FP due to its porous structure and oxygen functional groups. The Co-Ni-P/FP electrode has an overpotential as low as 125 mV for HER and 320 mV for OER at the current density of 10 mA cm−2. Additionally, according to density functional theory (DFT) calculations, the Co atom added to the Ni-P nanosphere can lead to considerably more charge accumulation around the Co and Ni active sites, which greatly encourages the HER and OER processes. The novel porous support, FP, provides a fresh way the preparation of self-supporting electrodes. [Display omitted] • Filter paper is used to prepare the self-supporting electrode as the substrate. • The preparation method is simple and the properties are stable. • Rich oxygen-containing functional groups of FP promote deposition and dispersion. • Explore the excellent electrochemical performance of amorphous Co-Ni-P/FP by DFT. [ABSTRACT FROM AUTHOR]

In this paper, structural properties such as structure parameters, energy band structure, the density of state, and charge density of LaGaO3 are calculated from the cubic phase. The calculations have been performed using the pseudopotential and a plane wave method in the framework of density functional theory (DFT) with generalized gradient approximation (GGA) by the Quantum Espresso package. The results are in good agreement with the results of others.

[Display omitted] • Paper mill sludge ash (pm SA) was used as catalysts to activate PMS. • Aerobic calcination was conducive to the exposure/formation of octahedral FeIII. • The O O bond fracture was the root pathway for FeIV O production. • The release of solid calcium in pm SA could inhibit the active decay of FeIV O. • The pm SA could effectively degrade similar pollutants in near-neutral water. The excellent performance of high-valent iron-oxo species (FeIV O) in the degradation of pollutants by activating peroxymonosulfate (PMS) had attracted much attention. However, the generation and reaction mechanisms were still unclear. In this study, iron-rich paper mill sludge was used as a raw material for the first time to prepare iron-based catalysts with abundant octahedral FeIII sites (Fe oct III). The results showed that the highest content of Fe oct III was found in the paper mill sludge ash obtained by aerobic calcination at 800 °C (pm SA800), and the pm SA800 could exhibit excellent catalytic activity (0.4785 min−1) and stability during the oxytetracycline (OTC) degradation process. The characterization and density functional theory (DFT) calculations further indicated that the Fe oct III was the dominant active site for FeIV O production. PMS tended to be adsorbed on two adjacent Fe oct III sites to form a [Fe oct III-OSO 2 OO(H)-Fe oct III] complex with a two-site adsorption configuration. Subsequently, the O O and O H bonds in [Fe oct III-OSO 2 OO(H)-Fe oct III] broken by absorbing energy, generating FeIV O. It's worth noting that the Ca species of pm SA800 effectively stabilized the pH of the reaction solution, which ensured the stable and continuous production of FeIV O. This work provides a new idea and insight for preparing catalysts that could produce FeIV O active species. [ABSTRACT FROM AUTHOR]

In this work, the structural, electronic, and optical properties of bulk and monolayer of Iron dichalcogenides FeX2 (X= S, Se, Te) have been investigated using the full potential linearized augmented plane wave (FP-LAPW) in the framework of density functional theory (DFT) with Wien2k simulation package. The calculated results show that FeX2 compounds in the bulk structure are non-magnetic semiconductors with a direct gap at the Γ point, while the monolayer compounds are ferromagnetic with metallic character. The band structure and energy gap of bulk and monolayer structures of FeX2 are calculated using GGA-PBE and GGA-mbj approximations that Becke-Johnson functional gives us better results for band gaps. All-optical properties such as real and imaginary parts of the dielectric function, absorption and reflection coefficients, refractive and extinction index, conductivity, and electron energy loss spectrum have been calculated and analyzed for bulk and monolayer. The High amplitude and wide absorption coefficient in the visible and ultraviolet region make these compounds a good candidate for use in photoelectric instruments and solar cells. Since monolayer compounds show magnetic properties, all calculations for monolayer compounds are performed in the spin-polarized form.

[Display omitted] • Catalytic properties of MoS 2 in presence of glucose has been studied using DFT. • Molecular level substrate-analyte interaction has been studied through NCI plot. • Mos 2 functionalized paper based electrochemical sensor for glucose has been developed. • The paper based electrochemical sensor shows good accuracy and selectivity. • The ML-driven smart app, GluQuantify, shows enhanced accuracy and resolution. A paper-based electrochemical sensor utilizing MoS 2 as sensing material is developed to quantitatively estimate glucose in a complex extracellular fluid matrix. The contribution of MoS 2 as sensing material is substantiated in the context of density functional theory formalism. The molecular modelling of MoS 2 and glucose interaction is elucidated through the theoretical estimation of non-covalent interactions and charge density difference plots. The charge transfer phenomenon during the oxidation of glucose molecule in electrochemical experiments is verified through electronic band structure analysis and frontier orbital theory. The electrochemical responses indicate that the sensor exhibits an average accuracy of nearly 96%, with a quantification limit of 100 nM. Furthermore, the chronoamperometric measurements highlight the superior sensitivity of the device in presence of various perturbing molecules. The obtained DPV responses were integrated with a robust machine learning-driven standalone app GluQuantify. This app precisely predicts the glucose concentrations in serum samples. The utilization of GluQuantify substantially elevates the overall accuracy of the sensing platform to 99% and automates the detection process. The application also enhances the resolution of the sensor to 0.01 µM, which mitigates the sensor resolution-related issues in manual estimation. [ABSTRACT FROM AUTHOR]

[Display omitted] • N-BPQD was synthesized through a solvothermal method using formamide as N source and solvent. • The N-BPQD exhibit a bright blue fluorescence with high quantum yield of 73.7%. • N-BPQD on fPAD was used as a visual fluorescent sensing platform for detection of bilirubin. • The fluorescent sensor shows high sensitivity and selectivity to bilirubin. • N-BPQD was a good fluorescent probe for cellular imaging. A facile top down producing approach for synthesis and doping of a nitrogen doped black phosphorus quantum dots (N-BPQD) in one-pot was developed by solvothermal method with formamide as a nitrogen source and solvent. The nitrogen atoms had introduced into BPQD structure and exhibit a bright blue photoluminescent with a high quantum yield of 73.7 %. The morphology and chemical structure of N-BPQD was characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. A fluorescent paper analysis device (fPAD) was applied in rapid and cost-effective detection of biomarker bilirubin with naked eyes. The fPAD sensor present a high selectivity, stability and sensitive response to bilirubin in a wide linear range of 10 to 150 µM with a limit of detection limit as 26 nM (S/N = 3) and limit of quantitation as 86 nM (S/N = 10). The principles-based density functional theory, calculations on doping and binding energy of N-BPQD were analyzed via the density functional theory (DFT) simulations. Moreover, N-BPQD showed extremely low cytotoxicity, which is a promising as a good fluorescent probe for stem cell imaging application. This work provide a new platform for diagnosis of jaundice disease. [ABSTRACT FROM AUTHOR]

Sluggish CO2 reduction reaction (CO2RR) and evolution reaction (CO2ER) kinetics at cathodes seriously hamper the applications of Li-CO2 batteries, which have attracted vast attention as one kind of promising carbon-neutral technology. Two-dimensional transition metal dichalcogenides (TMDs) have shown great potential as the bidirectional catalysts for CO2 redox, but how to achieve a high exposure of dual active sites of TMDs with CO2RR/CO2ER activities remains a challenge. Herein, a bidirectional catalyst that vertically growing MoS2 on Co9S8 supported by carbon paper (V-MoS2/Co9S8@CP) has been designed with abundant edge as active sites for both CO2RR and CO2ER, improves the interfacial conductivity, and modulates the electron transportation pathway along the basal planes. As evidenced by the outstanding energy efficiency of 81.2% and ultra-small voltage gap of 0.68 V at 20 µA cm-2, Li-CO2 batteries with V-MoS2/Co9S8@CP show superior performance compared with horizontally growing MoS2 on Co9S8 (H-MoS2/Co9S8@CP), MoS2@CP, and Co9S8@CP. Density functional theory calculations help reveal the relationship between performance and structure and demonstrate the synergistic effect between MoS2 edge sites and Co9S8. This work provides an avenue to understand and realize rationally designed electronic contact of TMDs with specified crystal facets, but more importantly, provides a feasible guide for the design of high-performance cathodic catalyst materials in Li-CO2 batteries. [ABSTRACT FROM AUTHOR]

• 2,2′:6′,2′'-terpyridine-4′-thiol (STpy) functionalization on Au NP--carbon paper and ITO. • DFT for geometry optimization and the electronic energy state calculation. • PEC and photocatalytic detoxification of Cr(VI) by cyclic voltammetry. • Cr(VI) reduction significantly enhanced upon STpy functionalization. • XPS confirmed Cr(VI) reduction on the surface of CP-AuNP-STpy. Detoxification of hexavalent chromium (Cr(VI)) in the environment and development of corresponding new materials and detoxification protocols have actively been studied and applied. Herein, 2,2′:6′,2′'-terpyridine-4′-thiol (STpy) was functionalized on Au nanoparticle (NP)-loaded carbon paper (CP) and indium-tin-oxide (ITO) electrodes (CP-AuNP and ITO-AuNP, respectively), and the photoelectrochemical (PEC) and photocatalytic detoxification of Cr(VI) using the resulting electrodes was investigated by cyclic voltammetry. Density functional theory at the B3LYP/6-31G level was used for geometry optimization, and the electronic energy state calculation was conducted at the TD-SCF/DFT/B3LYP level. For bare CP, ITO, and STpy-modified AuNP electrodes, the reduction potentials of Cr(VI) were around + 0.3, −0.2 V, and + 0.5 V (vs. Ag/AgCl), respectively. The PEC and photocatalytic Cr(VI) reduction performance of CP-AuNP was significantly improved upon STpy functionalization. Thus, these newly developed functionalized systems can provide very useful information for further improving the detoxification performances for various hazardous metals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbohydrate-based fluorometric sensors 1 and 2 have been used to detect picric acid in the aqueous medium. • The detection limits of 1 and 2 for PA were calculated to be 0.094 µM and 0.013 µM, respectively. • The DFT-supported charge transfer and µ-µ interactions explained the fluorescence quenching mechanism. • The sugar moiety plays a role in developing interaction between the sensor and PA in aqueous medium. • Both the sensors were used as naked-eye colorimetric sensors for PA in the test trips. Triazole-linked pyrene-appended inexpensive sensors 1 and 2 were synthesized from carbohydrates to instantly recognize picric acid (PA) based on a charge-transfer mechanism in the semi-water medium. Both sensors showed good selectivity and sensitivity towards PA over a wide variation of nitroaromatics in the absorbance and fluorescence methods. Moreover, sensors 1 and 2 were used for quick finding of picric acids using test strips. Interestingly, it was found that the sensitivity of 2 (LOD: 0.012 µM) is higher than 1 (LOD: 0.093 µM) might be explained by the close intramolecular space of the triazole/sugar residue and pyrene in sensor 2. The fluorescence quenching and structural features of the complexes (1-PA, 2-PA) were supported by density functional theory (DFT) calculations and spectroscopic studies. [ABSTRACT FROM AUTHOR]

The present study employs density functional theory-based first principle calculation to investigate the electron transport properties of polyaniline following exposure to acidic and alkaline pH. In-situ deposited polyaniline-based paper device maintains emeraldine salt form while it is exposed to acidic pH and converts to emeraldine base when it is subjected to alkaline pH solutions. These structural changes at acidic and alkaline pH are validated experimentally by Raman spectra. Furthermore, the Raman spectra computed from density functional theory are validated with the experimental spectra. The changes in the theoretical energy band gap of polyaniline obtained from first principle calculations were correlated with the changes in the experimental impedimetric response of the sensor after exposure to acidic and alkaline solutions. Finally, the impedimetric responses were used to predict urine pH through a machine learning based smart and interactive web application. Different machine learning based regression models were implemented to acquire the best possible outcome. Gradient Boosting Regressor with least square loss model was selected as it showed lowest mean square, mean absolute, and root mean square error than other models. The smart sensing platform successfully predicts the unknown pH of urine samples with an average accuracy of more than 98%. The locally deployed smart web app can be accessed within a local area network by the end-user, which holds promise towards effective detection of urinary pH. [Display omitted] [ABSTRACT FROM AUTHOR]

Partial discharge (PD) characteristics of hexadecane were studied in a needle-plane electrode geometry under AC field with a tungsten needle of 20 μm tip radius. PD experiments were conducted on samples containing known concentrations of oil/paper degradation compounds. Partial discharge inception voltage (PDIV), streamer repetition rates, and phase resolved PD (PRPD) patterns were acquired. Ionization potentials (IP) and electron affinities (EA) of hexadecane and a selection of additives were calculated with density functional theory (DFT) and correlated to PD characteristics. IP did not have a significant effect on the number of streamers initiated as most additives had higher IP relative to hexadecane. The presence of electronegative oxygen changes substantially the PD characteristics and, for most additives, increases the number of positive and negative streamers initiated. The greatest changes in PD characteristics, a reduced number of negative streamers, was observed for compounds with large electron capture cross section, even those with negative EA. [ABSTRACT FROM AUTHOR]

We propose an effective method for the detection and identification of dangerous substances by using the broadband THz pulse. This pulse excites, for example, many vibrational or rotational energy levels of molecules simultaneously. By analyzing the time-dependent spectrum of the THz pulse transmitted through or reflected from a substance, we follow the average response spectrum dynamics. Comparing the absorption and emission spectrum dynamics of a substance under analysis with the corresponding data for a standard substance, one can detect and identify the substance under real conditions taking into account the influence of packing material, water vapor and substance surface. For quality assessment of the standard substance detection in the signal under analysis, we propose time-dependent integral correlation criteria. Restrictions of usually used detection and identification methods, based on a comparison between the absorption frequencies of a substance under analysis and a standard substance, are demonstrated using a physical experiment with paper napkins. [ABSTRACT FROM AUTHOR]

With an increasing number of new scientific papers being released, it becomes harder for researchers to be aware of recent articles in their field of study. Accurately classifying papers is a first step in the direction of personalized catering and easy access to research of interest. The field of Density Functional Theory (DFT) in particular is a good example of a methodology used in very different studies, and interconnected disciplines, which has a very strong community publishing many research articles. We devise a new unsupervised method for classifying publications, based on topic modeling, and use a DFT-related selection of documents as a use case. We first create topics from word analysis and clustering of the abstracts from the publications, then attribute each publication/paper to a topic based on word similarity. We then make interesting observations by analyzing connections between the topics and publishers, journals, country or year of publication. The proposed approach is general, and can be applied to analyze publication and citation trends in other areas of study, beyond the field of Density Function Theory. [ABSTRACT FROM AUTHOR]

An accelerated thermal aging process was used to simulate the condition of paper insulation in transformer oil-paper systems. Optical parameters of the insulation paper after various aging intervals were analyzed with terahertz time-domain spectroscopy (THz-TDS) over the range 0.1~1.8 THz. The result shows that the paper had seven absorption peaks at 0.19, 0.49, 0.82, 1.19, 1.43, 1.53, and 1.74 THz, and density functional theory of B3LYP/6-311G+ (d, p) was used to simulate the molecular dynamics of the repeating component (cellobiose) of the cellulose paper. Theoretical spectra were consistent with experiment, which had absorption peaks at 0.18, 0.82, 1.47, and 1.53 THz in the same frequency range. At the same time, the paper samples after various aging intervals had different refractive indexes, and least squares fitting revealed a linear relationship between the degree of polymerization and the refractive index of the paper. Hence, this paper demonstrates that THz-TDS could be used to analyze the aging condition of transformer insulation paper and provides the theoretical and experimental basis for detection. [ABSTRACT FROM AUTHOR]

Although possessing well‐defined nanostructures and excellent multi‐electron redox properties, polyoxometalate clusters have poor intrinsic electrical conductivity and are prone to aggregation due to large surface energy, which makes them difficult to be fully utilized when applying as electrode materials for lithium‐ion batteries. In this paper, monodisperse K7MnV13O38 (MnV13) clusters are achieved by rationally utilizing nano‐sized high conductive carbon dots (CDs) as stabilizers. Benefiting from the fully exposed redox sites of MnV13 clusters (high utilization rate) and sufficient interfaces with carbon dots (extra interfacial energy storage), the optimized MnV13/10CDs anode delivers a high discharge capacity up to 1348 mAh g−1 at a current density of 0.1 A g−1 and exhibits superb rate/cycling capabilities. Density functional theory (DFT) calculations verify that ionic archway channels are formed between MnV13 and CDs, eliminating the bandgap and greatly improving the electron/ion conductivity of MnV13 and CDs. This paper paves a brand‐new way for synthesis of monodisperse clusters and maximization of extra interfacial energy storage. [ABSTRACT FROM AUTHOR]

This paper deals with the synergy between Nuclear Magnetic Resonance (NMR) spectroscopic investigations and DFT calculations, mainly of NMR parameters. Both the liquid and the solid states are discussed here. This text is a mix of published results supplemented with new findings. This paper deals with examples in which useful results could not have been obtained without combining NMR measurements and DFT calculations. Examples of such cases are tautomeric systems in which NMR data are calculated for the tautomers; hydrogen-bonded systems in which better XH bond lengths can be determined; cage compounds for which assignment cannot be made based on NMR data alone; revison of already published structures; ionic compounds for which reference data are not available; assignment of solid-state spectra and crystal forms; and the creation of libraries for biological molecules. In addition to these literature cases, a revision of a cage structure and substituent effects on pyrroles is also discussed. [ABSTRACT FROM AUTHOR]

The influence of pressure on the optical properties of nanostructured tetragonal Cu 2 Sb has been investigated jointly by experimental Raman spectroscopy (RS) and theoretical first-principles calculation based on density functional theory (DFT) varying pressure from zero (ambient condition) to 45 GPa. The DFT determined pressure dependence of the Raman active modes and the mode-Grüneisen parameters for each Raman mode are found to be in excellent agreement with those experimentally determined. Comparison of the pressure evolution of the experimental Raman data with those of DFT has allowed us to make the proper assignment of optical phonon modes. Image 1 • The Raman modes of the Cu 2 Sb were observed under high-pressures conditions. • The high-pressure in-situ data were supported by ab initio calculations. • The compressibility parameter of the Cu2Sb were obtained. • In-situ high-pressure Raman scattering and ab-initio studies in Cu2Sb up to 45 GPa. [ABSTRACT FROM AUTHOR]

In this paper, we explore the potential of LiMF3 (Lithium Metal Trifluoride) materials as electrode candidates by using density functional theory (DFT) calculations. We investigate their structural, electrochemical, and electrical properties and compare them with each other and some way with the most popular Li electrode materials. The structural properties of this kind of materials are interesting due to their 3D framework and somehow their openness of the diffusion channels, causing facile Li diffusion through the structure. We find that LiMnF3 has the best properties among the LiMF3 materials, with high structural stability (endurance of the lattice after Li ion extraction), low band-gap, suitable cell voltage, and high electrical rate-capability. LiMnF3 is especially favorable due to its environmental and toxicity advantages. After that, LiCoF3 shows appropriate properties. We also discuss the advantages and disadvantages of the other LiMF3 materials, namely LiNiF3, LiVF3, and LiFeF3, which they are also considerable electrodes. The voltage of the materials estimated to be 2, 2.6, 2.6, 3.4, and 3.1 V for M = Co, Fe, Ni, Mn, and V, respectively. This study provides a comprehensive evaluation of LiMF3 materials and suggests that they are promising candidates as Li-ion battery electrodes. This paper opens a new landscape for future investigations about these promising intercalation electrode materials. [ABSTRACT FROM AUTHOR]

The structural, mechanical, and thermoelectric characteristics of layered transition metal dichalcogenides MX 2 (M = Zr, Hf; X = S, Se) have been studied using density functional theory along with van der Waals correction. The exchange-correlation functional, enhanced with corrections for van der Waals interactions, has been evaluated for the hexagonal bulk structures of these materials. The analysis of elastic properties reveals that these compounds exhibit brittleness at zero pressure and conform to Born's criteria for mechanical stability. Examination of elastic constants and moduli suggests that the compounds possess reasonable machinability, moderate hardness, and anisotropy in terms of sound velocity. Transport properties, including the Seebeck coefficient, electrical conductivity, thermal conductivity, and power factor, have been computed using the semi-classical Boltzmann theory implemented in the BoltzTraP code. All investigated compounds exhibit excellent thermoelectric performance at high temperatures. This result suggests that our compounds are highly promising candidate for practical utilization in the thermoelectric scope., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The synthesis of two pyrazolone derivative compounds, PYR-I(4-Acetyl-1-(4-chlorophenyl)-3-isopropyl-1H-pyrazol-5(4H)-one) and PYR-II1-(4-Chlorophenyl))-3-isopropyl-5-oxo-4,5-5-dihydro-1H-pyrazole-4-carbaldehyde, their characterization by FT-IR, NMR, UV-Vis and GC-MS techniques, and the evaluation of the keto-enol tautomerization process of the structures along with the DFT approach and spectral data were reported in this paper. Spectral findings indicated that PYR-I was stable at the keto state. The IR spectrum recorded in solid form showed that the PYR-II structure was stable in the enol state, while the NMR spectrum in the solution medium showed that it was stable in the keto state. DFT-based analyses were realized with the B3LYP hybrid functional and the 6-311++G(d,p) basis set. The modelled keto, transition and enol state molecular geometries of structures were optimized in the gas phase and different solvent media and the total energy and dipole moment values were investigated at the specified theoretical level. The possible keto-enol tautomerism mechanism of the structures was evaluated through some thermodynamic parameters such as the difference in free Gibbs energy (ΔG), enthalpy (ΔH), entropy (ΔS), and predictive tautomeric equilibrium constants (K eq ), acidity constants (pK a ) and percentages of tautomers at 298.15 K and 1 atm pressure. The results of these analyses based on the DFT approach indicated that the keto-enol tautomer equilibrium heavily favours the keto form for PYR-I and the enol form for PYR-II in all cases. Moreover, natural bond orbital (NBO) analysis was performed for the tautomers, and the chemical reactivity profiles of the most stable tautomers were examined with the values of frontier molecular orbital energy and some reactivity descriptors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The binding affinities and interactions between eight drug candidates, both commercially available (candesartan; losartan; losartan carboxylic acid; nirmatrelvir; telmisartan) and newly synthesized benzimidazole-N-biphenyltetrazole (ACC519T), benzimidazole bis-N,N'-biphenyltetrazole (ACC519T(2) and 4-butyl-N,N-bis([2-(2H-tetrazol-5-yl)biphenyl-4-yl]) methyl (BV6), and the active site of angiotensin-converting enzyme-2 (ACE2) were evaluated for their potential as inhibitors against SARS-CoV-2 and regulators of ACE2 function through Density Functional Theory methodology and enzyme activity assays, respectively. Notably, telmisartan and ACC519T(2) exhibited pronounced binding affinities, forming strong interactions with ACE2's active center, favorably accepting proton from the guanidinium group of arginine273. The ordering of candidates by binding affinity and reactivity descriptors, emerged as telmisartan > ACC519T(2) > candesartan > ACC519T > losartan carboxylic acid > BV6 > losartan > nirmatrelvir. Proton transfers among the active center amino acids revealed their interconnectedness, highlighting a chain-like proton transfer involving tyrosine, phenylalanine, and histidine. Furthermore, these candidates revealed their potential antiviral abilities by influencing proton transfer within the ACE2 active site. Furthermore, through an in vitro pharmacological assays we determined that candesartan and the BV6 derivative, 4-butyl-N,N0-bis[20-2Htetrazol-5-yl)bipheyl-4-yl]methyl)imidazolium bromide (BV6(K + ) 2 ) also contain the capacity to increase ACE2 functional activity. This comprehensive analysis collectively underscores the promise of these compounds as potential therapeutic agents against SARS-CoV-2 by targeting crucial protein interactions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Indoor volatile formaldehyde is a serious health hazard. The development of low-temperature and efficient nonhomogeneous oxidation catalysts is crucial for protecting human health and the environment but is also quite challenging. Single-atom catalysts (SACs) with active centers and coordination environments that are precisely tunable at the atomic level exhibit excellent catalytic activity in many catalytic fields. Among two-dimensional materials, the nonmagnetic monolayer material g-C 3 N 4 may be a good platform for loading single atoms. In this study, the effect of nitrogen defect formation on the charge distribution of g-C 3 N 4 is discussed in detail using density functional theory (DFT) calculations. The effect of nitrogen defects on the activated molecular oxygen of Pt/C 3 N 4 was systematically revealed by DFT calculations in combination with molecular orbital theory. Two typical reaction mechanisms for the catalytic oxidation of formaldehyde were proposed based on the Eley-Rideal (E-R) mechanism. Pt/C 3 N 4 -V 3N was more advantageous for path 1, as determined by the activation energy barrier of the rate-determining step and product desorption. Finally, the active centers and chemical structures of Pt/C 3 N 4 and Pt/C 3 N 4 -V 3N were verified to have good stability at 375 K by determination of the migration energy barriers and ab initio molecular dynamics simulations. Therefore, the formation of N defects can effectively anchor single-atom Pt and provide additional active sites, which in turn activate molecular oxygen to efficiently catalyze the oxidation of formaldehyde. This study provides a better understanding of the mechanism of formaldehyde oxidation by single-atom Pt catalysts and a new idea for the development of Pt as well as other metal-based single-atom oxidation catalysts., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Cheng Zhang reports was provided by National Natural Science Foundation of China. Cheng Zhang reports a relationship with Huazhong University of Science and Technology that includes: non-financial support. nothing If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In this paper, we investigate the secondary structure of the Piv-Pro-d-Ser-NHMe peptide by means of nuclear magnetic resonance (NMR) and electronic circular dichroism (ECD) experiments, in conjunction with theoretical simulations based on molecular dynamics and time-dependent density functional theory calculations including polarizable embedding to account for solvent effects. The various experimental and theoretical protocols are assessed and validated, and are shown to provide a consistent description of the turn structure adopted by this peptide in solution. In addition, a simple fitting procedure is proposed to make the simulated and experimental ECD almost perfectly match. This full methodology is finally tested on another small peptide, enlightening its efficiency and robustness.

Furan-containing compounds distribute widely in food, herbal medicines, industrial synthetic products, and environmental media. These compounds can undergo oxidative metabolism catalyzed by cytochrome P450 enzymes (CYP450) within organisms, which may produce reactive products, possibly reacting with biomolecules to induce toxic effects. In this work, we performed DFT calculations to investigate the CYP450-mediated metabolic mechanism of furan-ring oxidation using 2-methylfuran as a model substrate, meanwhile, we studied the regioselective competition of another hydroxylation reaction involving methyl group of 2-methylfuran. As a result, we found the toxicological-relevant cis-enedione product can be produced from O-addition directly via a concerted manner without formation of an epoxide intermediate as traditionally believed. Moreover, our calculations demonstrate the kinetic and thermodynamic feasibility of both furan-ring oxidation and methyl hydroxylation pathways, although the former pathway is a bit more favorable. We then constructed a linear model to predict the rate-limiting activation energies (ΔE*) of O-addition with 11 diverse furan substates based on their adiabatic ionization potentials (AIPs) and condensation Fukui functions (CFFs). The results show a good predictive ability (R 2 =0.94, Q 2 CV =0.87). Therefore, AIP and CFF with clear physichem meanings relevant to the mechanism, emerge as pivotal molecular descriptors to enable the fast prediction of furan-ring oxidation reactivities for quick insight into the toxicological risk of furans, using just ground-state calculations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The contamination of wastewater with antibiotics has emerged as a critical global challenge, with profound implications for environmental integrity and human well-being. Adsorption techniques have been meticulously investigated and developed to mitigate and alleviate their effects. In this study, we have investigated the adsorption behaviour of Erythromycin (ERY), Gentamicin (GEN), Levofloxacin (LEVO), and Metronidazole (MET) antibiotics as pharmaceutical contaminants (PHCs) on amide-functionalized (RC (=O)NH 2 )/MIL-53 (Al) (AMD/ML53A), using molecular simulations and density functional theory (DFT) calculations. Based on our DFT calculations, it becomes apparent that the adsorption tendencies of antibiotics are predominantly governed by the presence of AMD functional groups on the adsorbent surface. Specifically, hydrogen bonding (HB) and van der Waals (vdW) interactions between antibiotics and AMD groups serve as the primary mechanisms facilitating adsorption. Furthermore, we have observed that the adsorption behaviors of these antibiotics are influenced by their respective functional groups, molecular shapes, and sizes. Our molecular simulations delved into how the AMD/ML53A surfaces interact with antibiotics as PHCs. Moreover, various chemical quantum descriptors based on Frontier Molecular Orbitals (FMO) were explored to elucidate the extent of AMD/ML53A adsorption and to assess potential alterations in their electronic properties throughout the adsorption process. Monte Carlo simulation showed that ERY molecules adsorb stronger to the adsorbent in acidic and basic conditions than other contaminants, with high energies: -404.47 kcal/mol in acidic and -6375.26 kcal/mol in basic environments. Molecular dynamics (MD) simulations revealed parallel orientation for the ERY molecule's adsorption on AMD/ML53A with 80% rejection rate. In conclusion, our study highlighted the importance of modeling in developing practical solutions for removing antibiotics as PHCs from wastewater. The insights gained from our calculations can facilitate the design of more effective adsorption materials, ultimately leading to a more hygienic and sustainable ecosystem., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Copper oxides are vital catalysts in facilitating the formation of polychlorinated thianthrenes/dibenzothiophenes (PCTA/DTs) through heterogeneous reactions in high-temperature industrial processes. Chlorothiophenols (CTPs) are the most crucial precursors for PCTA/DT formation. The initial step in this process is the metal-catalyzed production of chlorothiophenoxy radicals (CTPRs) from CTPs via dissociation reactions. This work combines density functional theory (DFT) calculations with ab initio molecular dynamics (AIMD) simulations to explore the formation mechanism of the adsorbed 2-CTPR from 2-CTP, with the assistance of CuO(111). Our study demonstrates that flat adsorption configurations of 2-CTP on the CuO(111) surface are more stable than vertical configurations. The CuO(111) surface acts as a strong catalyst, facilitating the dissociation of 2-CTP into the adsorbed 2-CTPR. Surface oxygen vacancies enhance the adsorption of 2-CTP on the CuO(111) surface, while moderately suppressing the dissociation of 2-CTP. More importantly, water molecules and surface hydroxyl groups actively promote the dissociation of 2-CTP. Specifically, water directly participates in the reaction through "water bridge", enabling a barrier-free process. This research provides molecular-level insights into the heterogeneous generation of dioxins with the catalysis of metal oxides in fly ash from static and dynamic aspects, providing novel approaches for reducing dioxin emissions and establishing dioxin control strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)