CONTEXT: Oligothiophenes have long been used as model compounds to understand the chemistry of polythiophenes. Herein, we have some quantum chemical calculations and intra- and inter-molecular interaction calculations of a series of oligothiophenes such as terthiophene, quintetthiophene, sevensthiophene, terthiophene-terthiophene, terthiophene-water, terthiophene-methanol, and terthiophene-chloroform performed by time-dependent density functional theory (TD-DFT), density functional theory (DFT), and Multiwfn: a multifunctional wavefunction analyzer. The UV-vis spectra, HOMO-LUMO energies, NBO analysis, MEP, molecular structures, and electronic properties were computed using DFT/TD-DFT at the level of B3LYP/6-31+ G (d,p) and described. The nature of molecular interactions between terthiophene and solvents like water, methanol, and chloroform were also investigated using non-covalent interaction index (NCI), reduced density gradient (RDG), localized orbital locator (LOL), and electron localization function (ELF) topological analyses. Besides, Fukui functions and energy of population density-of-states were computed using the same method. The calculation results show that there are some changes in the terthiophene with the addition of solvent to the medium. METHODS: DFT calculations were performed using the Gaussian 09 software and GaussView 5.0 visulation program. Multiwfn software is used to calculate the reduced density gradient (RDG) scatterplots, non-covalent interactions (NCI), ELF, LOL, Fukui analysis, and energy of population density-of-states of oligothiophenes.

CONTEXT: Oxygen is a chemically active gas. Metal uranium will be rapidly oxidized when exposed to oxygen directly, forming a complex and uncompacted oxide layer on the surface. The U-O2 reaction system is a very complex metal oxidation system. The surface oxidation reaction of uranium-niobium alloy is more complex, and it is also the main corrosion form of uranium-niobium alloy. Exploring the microscopic mechanism of surface oxidation corrosion of uranium-niobium alloy is of great significance for understanding the surface corrosion phenomenon in practical applications. The adsorption of O2 on U-Nb (5at.%) surface was investigated by first-principles calculation using a periodic slab model within the density functional theory (DFT). The effect of different levels of Nb doping on O adsorption was investigated, and the stability of O-U and O-Nb adsorption was studied in conjunction with the Bader charge distribution, differential charge density map, electron density of states, and surface work function. The results showed that physical adsorption happens when O2 is vertically adsorbed at the top site of Nb atom, whereas dissociative adsorption happened in all other configurations considered here. The interaction between adsorbed O2 and U-Nb surface was essentially the hybridization between the O/2p orbital electrons and the U/6d, U/5f, Nb/4p, Nb/5s, and Nb/4d orbital electrons to form a relatively stable ionic bond. When Nb was doped into the second layer of the surface, the most stable O2 adsorption configuration was top-site horizontal adsorption. The adsorption energy was - 22.38 eV, which was more negative than the adsorption energy of - 21.38 eV for the first doped layer horizontal adsorption at hollow-site. The interaction was essentially the hybridization between O/2p orbital electrons and U/6d and U/5f electrons and between O/2s orbital electrons and U/6p orbital electrons to form a relatively stable ionic bond. METHOD: In this paper, the adsorption and dissociation of oxygen molecules on the surface of U-Nb system were systematically studied by first-principles calculations, in order to explore the surface oxidation corrosion mechanism of uranium-niobium alloy from the micro level. The VASP program uses PAW pseudopotential, which belongs to the density functional method, and uses DSP.

In this present work, we calculate the electronic, spectroscopic and nonlinear optical properties (NLO) of N-dialkyl-imidazolium hexafluorophosphate (CNMIM.PF6, where N = 10, 12, 14, 16, 18, 20) ionic liquid crystal molecules under the effect of alkyl chain length variation in cation moiety [CNMIM]+ with fixed anion [PF6]-. CONTEXT: The majority of research on ionic liquid crystal to date has been focused on experiments, while theoretical studies on the optical properties of ionic liquid crystal have been extremely rare. Nonlinear phenomena in optical devices have attracted many researchers. Therefore, results of NLO properties may favor facile synthesis and fabrication of novel-type of materials as well as optoelectronic devices. Spectroscopic studies elucidate further insight into ionic liquid crystal behavior. The results demonstrate that variations in alkyl chain length have an impact on the conformers' electrical, spectroscopic, and NLO properties as well as their stability. The stability of ionic liquid crystal molecules increases with increase in the alkyl chain length and the energy band gap range is 6.64-6.29 eV. Understanding ionic liquid crystal's physical behavior requires an understanding of their dipole moments and NLO features, which are covered in this article. The results of NLO characteristics for all ionic liquid crystal molecules show that their first-order hyperpolarizabilities are higher than the reference molecule (urea). METHODS: The electronic (molecular energy band gap, electrostatic potential map, as well as HOMO-LUMO orbitals) and spectroscopic (IR-RAMAN, UV) properties were evaluated with the help of theoretical model at B3LYP/6-31G(d) while the NLO study has been performed using B3LYP and M06-2X with different basis sets 6-31G(d) and 6-311++G(d,p), as implemented in Gaussian09 software.

CONTEXT: Developing novel materials present a great challenge to improve the photovoltaic performance of organic solar cells (OSCs). In this paper, we designed a series of the donor-π bridge-acceptor-π bridge-donor (D-π-A-π-D) structure molecules. These molecules consist of diketopyrrolopyrrole (DPP) moiety as core, 9-hexyl-carbazole moiety as terminal groups, and different planar electron-rich aromatic groups as π-bridges. The density functional theory (DFT) and time-dependent DFT (TD-DFT) computations showed that the frontier molecular orbital (FMO) energy levels, energy gaps, electron-driving forces (ΔEL-L), open-circuit voltage (Voc), fill factor (FF), reorganization energy (λ), exciton binding energy (Eb), and absorption spectra of the designed molecules can be effectively adjusted by the introduction of different π-bridges. The designed molecules have narrow energy gap and strong absorption spectra, which are beneficial for improving the photoelectric conversion efficiency of organic solar cells. In addition, the designed molecules possess large ΔEL-L, large Voc, and FF values and low Eb when the typical fullerene derivatives are used as acceptors. The FMO energy levels of the designed molecules can provide match well with the typical fullerene acceptors PC61BM, bisPC61BM, and PC71BM. Our results suggest that the designed molecules are expected to be promising donor materials for OSCs. METHODS: All DFT and TD-DFT calculations were carried out using the Gaussian 09 code. The computational technique chosen was the hybrid functional B3LYP and the 6-31G(d,p) basis set. The benzene and chloroform solvent effects have been considered using the polarized continuum model (PCM) at the TD-DFT level. The simulated absorption spectra of designed molecules were plotted by using the GaussSum 1.0 program.

CONTEXT: The potential of Ni-C72 and Ni-Al36P36 as effective catalysts for O3 decomposition is examined by LH and ER mechanisms. The activation barrier energy and Gibbs free energy of reaction steps for O3 decomposition on Ni-C72 and Ni-Al36P36 are calculated. The ∆Eformation of Ni-C72 and Ni-Al36P36 are negative values and these structures are stable nano-catalysts. The Ni atoms are catalytic positions to adsorb the O3 and other important species of O3 decomposition by LH and ER mechanisms. The Ni-Al36P36 for O3 decomposition has lower Eacivation and more negative ∆Greaction than Ni-C72. The Eacivation value of rate-determining step for O3 decomposition by LH mechanism is lower than ER mechanism. The Ni-C72 and Ni-Al36P36 can catalyze the reaction steps of O3 decomposition by LH and ER mechanisms. METHODS: The structures of Ni-C72 and Ni-Al36P36 nanocages and their complexes with O3 and other important species of are optimized by PW91PW91/6-311 + G (2d, 2p) model and M06-2X/cc-pVQZ model in GAMESS software. The strcutures of nanocages and their complexes with important species of O3 decomposition by LH and ER mechanisms are optimized and their frequencies are calculated in order to demonstrate that these structures are real minima on the potential energy surface.

CONTEXT: The morphology of adsorption isotherms embodies a wealth of information regarding various adsorption mechanisms, rendering the classification and identification methodologies predicated on the shape of adsorption isotherms indispensably crucial. While research on classification techniques has been extensively developed, traditional methods of adsorption isotherm identification grapple with inefficiencies and a high margin of error. Neural network-based methodologies for adsorption isotherm identification serve as a countermeasure to these shortcomings, as they facilitate swift online identification while delivering precise results. In this paper, we deploy a hybrid of convolutional neural networks (CNN) and long short-term memory (LSTM) networks for the identification of adsorption isotherms. Extensive theoretical adsorption isotherms are generated via adsorption equations, forming a comprehensive training database, thereby circumventing the need for time-consuming and costly repetitive experiments. The F1-score, receiver operating characteristic (ROC) curves, and area under the ROC curve (AUC) are introduced as criteria to evaluate the identification performance and generalization ability of the model during the testing phase. The results highlight the model's superlative performance in the task of adsorption isotherm identification, with accuracy rates of 100% in both the training and validation sets. The mean F1-score obtained from the testing set reached 0.8885, with both macro-average and micro-average AUC exceeding 0.95. METHOD: PyCharm was employed as an experimental and testing platform, with Python 3.9 serving as the programming language. TensorFlow 2.11.0 and Keras 2.10.0 were harnessed for the training and testing of CNN-LSTM, while numpy 1.21.5 and scipy 1.81 were utilized for the creation of training and validation datasets.

CONTEXT: This study rigorously investigates three 3d transition metal carbide (TMC) structures via LDA and GGA approximations. It examines cohesive energy (Ecoh), Vickers hardness (Hv), mechanical stability, and electronic properties. Notably, most 3d TMCs exhibit higher cohesive energy than nitrides, and rs-TiC demonstrates a Vickers hardness of 25.66 GPa, outperforming its nitride counterpart. The study employs theoretical calculations to expedite research, revealing mechanical stability in CrC and MnC (GGA) and CrC (LDA in cc structure), while all 3d TMCs in rs and seven in zb structures show stability. Charge transfer and bonding analysis reveal enhanced covalency along the series, influenced by the interplay between p orbitals of carbon and d orbitals of the metal. Most 3d TMCs exhibit metallic properties, excluding zb-TiC and zb-FeC in all phases. An inverse correlation between elastic constant C44 and electronic states near the Fermi level (EF) emerges, guiding applications and design. This study efficiently uncovers 3d TMC properties, offering insights for applications and design. METHODS: We employed the Vienna ab initio Simulation software (VASP) to perform computations based on density functional theory (DFT). Our approach incorporated both the projector augmented wave (PAW) and PW91 general gradient approximation (GGA) methods within the local density approximation (LDA).

CONTEXT: It is known that methylating agents methylate DNA by transferring a methyl cation (CH3+) to the nucleophilic sites in DNA bases and DNA methylation is implicated in cancer and other pathological conditions. Therefore, it is important to scavenge CH3+ ion in order to protect DNA from methylation. Graphene is considered to be a versatile material for use in a wide variety of fields including sensors, antioxidants, drug delivery and DNA sequencing. In this work, we have theoretically investigated the interaction of CH3+ ions with graphene surface with an aim to understand if pristine graphene can be used as a substrate to adsorb CH3+ cations generated from harmful methylating agents. The computed adsorption energies show that adsorption of one, two and three CH3+ ions on graphene is favourable as the adducts thus formed are found to be substantially stable in both gas phase and aqueous media. The Bader charge transfer analysis and density of states (DOS) calculation also indicate a strong interaction between graphene and CH3+ ions. Thus, our results show that pristine graphene can be used as a substrate to scavenge CH3+ ions. METHODS: The spin polarised density functional theory (DFT) calculations employing PBE functional, ultrasoft pseudopotentials and plane wave basis set having kinetic energy cut-offs of 40 Ry and 400 Ry, respectively, for wave functions and charge densities were carried out to study the adsorption of CH3+ ion(s) on the pristine graphene surface. The Grimme's DFT-D2 method was used for the estimation of van der Waals interactions. The 'dipole correction' along z-direction was also applied for adsorption study. The Marzari-Vanderbilt smearing and Monkhorst-Pack k-point grid were employed for the Brillouin zone sampling. A 6 × 6 graphene supercell with a vertical cell dimension of 18 Å was considered for the adsorption study. The charge transfer between the CH3+ ion(s) and graphene was estimated using Bader charge analysis. The implicit solvation model (SCCS) was used to estimate the solvent effect of aqueous media. All the calculations were performed using QUANTUM ESPRESSO package.

CONTEXT: In this work, the corrosion inhibitive effect of acetoxime derivative of zinc chloride, (ZnCl2.2HON=C(CH3)2) (ZA), was investigated on mild steel in epoxy/polyamide coating. ZA was used to modify diglycidyl ether of bisphenol A (DGEBA) to yield novel anticorrosive coating (epoxy-ZA) with excellent barrier characteristic. The dispersal of ZA may lead to the formation of Zn-O-C and O-Zn-O linkages in the polymer framework which act as inorganic fillers producing a dense structure of hybrid coating. In electrochemical findings, electrochemical impedance spectroscopy (EIS) and Tafel polarization (TP) indicate higher protection efficiency for epoxy-ZA coatings (99.99 and 99.93 % for EIS and TP, respectively) as compared to others. Using surface analysis and electrochemical data, it was concluded that an inhibition synergy was developed when ZA was taken instead of acetoxime or zinc chloride (ZC) alone in the coating formulation. METHODS: Fourier transform infrared (FT-IR) was used to investigate epoxy interaction with zinc compounds and scanning electron microscopy (SEM) was used to investigate morphology of the samples. To reinforce the experimental results, reactivity of crosslinked epoxy and epoxy-ZA coatings with metallic surface was also explored using density functional theory (DFT) with basis set B3LYP/6-311G(d,p) and molecular dynamics (MD) methods by using Forcite module. Modification of epoxy with ZA enhances its interaction with steel surface in dry as well as in wet conditions as indicated by the adhesion energy calculated by MD simulations.

CONTEXT: Various concentrations of (E)-4-methoxy-N'-(2-(trifluoromethyl)benzylidene) benzohydrazide (EMT) adsorbed on colloidal silver nanoparticles were studied using SERS and results were compared to the normal Raman spectrum. DFT calculations were used to validate experimental findings. Theoretically, the structures of the EMT and EMT-Ag6 systems were optimized. The UV-Vis spectral analysis's red shift and lower intensity behavior show that EMT has chemisorbed onto Ag nanoparticles. Charge transfer (CT) from Ag to EMT is highlighted by FMO analysis. The CT interaction in EMT and EMT-Ag6 was further verified by MEP and Mulliken charge analyses. The EMT was adsorbed on Ag nanoparticles with tilted orientation and orientation changes with colloidal concentration, according to SERS spectrum analysis. Docking EMT with 4PQE and 5DYW binding affinities are found to be -9.7 and -8.1 kcal/mol. MD simulations give the competence of 5DYW-EMT and 4PQE-EMT in their intended binding interactions and their ability to establish enduring associations with the protein of interest. METHODS: DFT was used to optimize the molecular structures of EMT and EMT-Ag6 using B3LYP/6-311++G* (LANL2DZ basis set for Ag). A molecular dynamics simulation study was conducted on the 4PQE-EMT and 5DYW-EMT systems using the Desmond software for 100 ns.

CONTEXT: Triazene compounds (-NNN(H)-) exhibit versatility in biological, physical, and chemical applications. In their anionic form (-NNN-)(-), they can act as coordinating sites for metals, forming metallic complexes. In this study, two new isomeric triazene compounds with meta- and para-substituents in their neutral and anionic forms were investigated. A combination of detailed experimental spectroscopic characterization and computational chemistry analyses were employed. The new compounds, 1-(2-benzamide)-3-(3-nitrophenyl) triazene (m-TZN) and 1-(2-benzamide)-3-(4-nitrophenyl) triazene (p-TZN), were compared to 1,3-diphenyltriazene (dph-TZN) to understand the effects of functionalization and targeted triazene deprotonation. The anionic forms are stable, and our investigation suggests that these new compounds are suitable tridentate ligands that can act as chelating agents for metallic cations in stable complexes, similar to those found in vitamin B12. METHODS: The absorption, vibrational, and electronic properties of the newly synthesized triazene compounds were extensively characterized using FT-IR/FT-Raman and UV-Vis spectroscopy. Their distinct molecular properties, intramolecular hydrogen bond effects, stability, and electronic transitions were investigated using the ORCA software. These analyses involved DFT and TD-DFT calculations at the ωB97X-D3/Def2-TZVP level of theory with THF CPCM implicit solvation to determine the molecular topology and electronic structure. The advanced STEOM-DLPNO-CCSD method for excited states was employed, enabling an in-depth analysis of ground and excited-state chemistry, accounting for precise electronic correlation and solvation effects. Explicit THF solvation was tested on the full TD-DFT ωB97X-D3/Def2-TZVP level and using ONIOM on the STEOM calculation. Reactivity was studied using Fukui functions, and action as chelating agents was investigated using GFN-xTB2 and DFT.

CONTEXT: The bandgap of metal monochalcogenides (MMCs) is a key property that governs their physical and chemical properties. Accurate measurement of the bandgap is essential for a range of applications, including optoelectronics and photovoltaics. However, many theoretical approximations fail to accurately calculate the bandgap for MMCs, making it difficult to obtain precise values. This study investigated the suitability of the FP-LAPW/GAM-MPW1K scheme for determining the bandgap of MMCs. The investigation included lattice parameters, bandgap, band structure, and density of states, which were compared against both previous theoretical calculations and available experimental data. The findings of the study indicate that the FP-LAPW/GAM-MPW1K approach accurately calculates the bandgap value of MMCs by efficiently treating d-state electrons. The results are consistent with prior studies, confirming the method's reliability in determining the bandgap of these semiconductors. METHODS: our study used the GAM-MPW1K functional and the full potential linearized augmented plane wave method (FP-LAPW) in the ELK code to calculate the lattice parameters, electronic band structure, and bandgap of ZnS, ZnSe, ZnTe, CdS, CdSe, and CdTe compounds in the wurtzite structure. The crystallographic data were obtained from the COD database and the inputs were prepared by CIF2CELL code. The results were visualized using Xmgrace and VESTA software.

CONTEXT: Electroplated zinc layers have shown excellent corrosion resistance, especially those are stable in the atmosphere after the passivation, and therefore zinc electroplating is widely used in various fields such has mechanical, vehicle, construction, and ironware industries. Benzalacetone (BA) was reported as brighteners for zinc deposition, while polyoxyethylene nonylphenylether (NP) was used as levelers or carriers for zinc electroplating. Sodium benzoate (SB) and dispersant NNO cooperatively act as auxiliary additives. Quantum chemical parameters (QCPs) of four additives were calculated by using DFT, and MD simulations were performed. By comparing binding energies of four additives (benzalacetone (BA), sodium benzoate (SB), polyoxyethylene nonylphenylether (NP) and dispersant NNO), with Zn (001) surface, BA has the lowest binding energy, which is due to the lowest hardness parameter, and NNO has the highest binding energy, which is due to the highest dipole moment despite its small hardness parameter. METHODS: For DFT calculation, NWChem was employed, which uses the Gaussian basis set. The B3LYP functional was used for exchange-correlation interaction between electrons, and the 6-311G+ (d,p) basis sets were used for all the atoms. Solvation effect was considered by using COSMO (COnductor-like Screening MOdel), in which the dielectric constant of solvent was set to 78.54 of water. For dispersion correction, DFT-D method of Tkatchenko and Scheffler (TS) was used. MD simulations were performed by using GULP (General Utility Lattice Program) code with Dreiding forcefield and atomic Hirshfeld charges from DFT calculations. MD simulations were performed on the conditions of NVT ensemble with a step of 1 fs and simulation time of 500 ps at 298 K and 323 K. To consider solvation effect, 1,000 water molecules were inserted into the box.

CONTEXT: nanoKAZ is a compact luciferase that exhibits intense blue light emission when it catalyzes the substrate Furimazine (FMZ) as a luciferin, making it an excellent candidate as a reporter protein. However, the specific catalytic residues and mechanism of nanoKAZ have not been revealed. Recently, the structure of nanoKAZ was determined, and it was observed that the luminescent properties changed when FMZ analogs with naphthalene replacing benzene were used. It is speculated that the substituted naphthalene may influence the interaction between the catalytic residues and luciferins, thereby affecting the energy of the emitted light signal. METHOD: Therefore, the primary objective of this study is to analyze and compare the molecular recognition between nanoKAZ and FMZ along with its four activity-altered naphthalene analogs, with aiming to identify the catalytic residues. Molecular docking was employed to construct all nanoKAZ-luciferin models, followed by a 500 ns molecular dynamics simulation. The simulation trajectory was subjected to MM/PBSA analysis to identify crucial residues that contribute significantly to luciferin binding. In the result, two polar residues Y109, and R162 were identified as active residues as their notable contributions to the binding energy. Subsequently, an oxygen molecule was introduced into the local region of the nanoKAZ-FMZ complex and followed with quantum chemical calculations (semiempirical and DFT methods were used) to investigate the catalysis details. The results illustrated the involvement of Y109 and R162 in the oxygenation of FMZ, leading to the formation of dioxetanone, which has been suggested as an important intermediate in the oxidation process among various luciferins sharing the same functional group as FMZ.

CONTEXT: Macrocyclic extractants capture cations in solution phase; therefore, their structures and energetics in different solvents are worth investigating. In this computational research work, the optimized geometry of three aza-18-crown-6 extractants (1-3) has been obtained in suitable solvent mediums to work out the influence of the solvation on their binding affinity with Sr2+. The designed macrocyclic extractants are remarkable as the N-substituted side chain bears the rarely examined simple aliphatic unsaturated double and triple bond. All significant structural perturbations of the macro ring wherein Sr2+ binds are examined. Prediction of the auxiliary effect of the simple aliphatic unsaturated side arm on the binding of Sr2+ through solvent competition or cation-pi interaction is undertaken. The binding affinity of the complex formed in the solvent and gas phases is calculated. Results obtained in this study favor the utilization of solvents of low dielectric constant (CHCl3 and DCM) for effective binding of Sr2+ ions by the extractants. METHOD: All DFT calculations were performed using the Gaussian 09 program. The optimized geometries and their structural features were visualized by GaussView. Density functional calculation involving B3LYP functional and LANL2DZ basis set was employed to obtain optimized geometry and energy of the extractants and their Sr2+ complex. The solvation effects were considered by employing the calculations with the polarized continuum model (PCM). The computational method's reliability was assured by comparing the optimized structure with that of X-ray reported structure of a similar type of complex.

CONTEXT: Isoniazid (INH) is one of the medications most used for tuberculosis (TB) treatment. However, long-term continuous therapy can cause hepatotoxicity and peripheral neuritis. The degradation of INH is an important aspect of the research in the field of drug stability as well as drug formulation for controlling release. It is thought that tautomerization, hydrolysis as well as nucleophilic substitutions can cause decrease in INH as non-enzymatic degradation. Therefore, it is crucial to understand the mechanisms and energies of the major reactions in order to provide reference for future drug formulation and application. This study is an effort to understand the kinetic and thermodynamic properties of the non-enzymatic degradation reactions. The chemical reaction phenomena are investigated using the density functional theory (DFT) method. This study shows that major degradation of INH can be done via tautomerization followed by hydrolysis. The general trends in nucleophilic degradation presented here are consistent with experimental pKa of nucleophiles. METHODS: All DFT calculations were performed using the Gaussian Software Packages (Gaussian 09 revision B.01 and GaussView 5.0.8). MOLEKEL 4.3 software was utilized to visualize the molecular graphics of all relevant species. The optimized molecular geometries were calculated using B3LYP/6-311 + G(d,p) level in the gas phase. The IEF-PCM/B3LYP/6-311 + G(d,p) level was selected for single-point and frequency calculations in aqueous media.

CONTEXT: The mechanical characteristics and deformation behavior of Cu material under the nanoscratching through a diamond tooltip on the workpiece are studied using molecular dynamics (MD) simulation. Effects of scratching velocity, scratching depth, workpiece temperature, and grain size on the total force, shear strain, pile-up, shear stress, workpiece temperature, and phase transformation are investigated. The results reveal that increasing the scratching velocity leads to higher oscillation in total force, greater shear strain and shear stress, higher pile-up on the workpiece surface, and higher workpiece temperatures. The effect of the scratching velocity on phase transformation shows that most of the dislocation is a transformation structure from the FCC structure to the HCP, BCC, and other structures in all workpieces during the nanoscratching process. In addition, with increasing the scratching depth, material pile-up becomes more prominent, consequently elevating the contact area between the diamond tooltip and the workpiece, which simultaneously leads to an increase in total force, shear strain, pile-up, shear stress, and workpiece temperature. The MD simulation results revealed that the subsurface region of nanoscratched Cu single-crystal experiences the formation of stacking faults, vacancy defects, and cluster vacancies. In studying the effect of workpiece temperature, the results show that higher temperatures lead to the decline of scratching force, high plastic deformation, increased shear strain and stress, lower pile-up height, and high transition from the FCC structure to both other and BCC structures. For polycrystalline structures, the force curves occur in the oscillation state in all cases of different grain sizes because of the dislocation deformation during the cutting process. The maximum force decreases with diminishing grain size, attributed to the inverse Hall-Petch relation. As the grain size increases, leading to a decrease in the shear strain, stress, and an uneven pile up; also, the HCP structure rises with decreasing grain boundary and the partial dislocation and stacking fault mobilize inside grains. METHODS: By using molecular dynamics (MD) simulation based on the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) software, all molecular interactions were described by the Lennard-Jones (LJ) and embedded atom method (EAM) potentials. In order to mitigate the effects of temperature fluctuations, the system employs an isothermal and isobaric (NPT) ensemble for precise temperature control. The temperature was set as 300 K and the time step was 1 fs (femtosecond).

CONTEXT: Reactive molecular dynamics simulations were performed to study the decomposition processes of 1,3,5-trinitro-1,3,5-triazine (RDX) crystal under high temperatures (2100, 2400, 2700, and 3000 K) and detonation pressure (34.5 GPa) and 0 GPa. It is found that the initial decomposition paths of RDX under different temperatures coupled with detonation pressure are similar, which is due to the N-NO2 bond breakage to release NO2. The formation rates of N2 and H2O are significantly affected by temperature, while those of CO2 are less influenced. The C atoms finally formed C clusters. As the temperature rises, the decomposition speeds up, indicating that the high temperature accelerates the decomposition. Applying pressure can reduce the reaction energy barrier and accelerate the decomposition. METHODS: The RDX model was constructed using the Materials Studio 7.0 package. All MD simulations were performed based on the ReaxFF force field in the LAMMPS software package, and the crystals were visualized using the OVITO software package. The time step was 0.1 fs, and the total MD simulation time was 200 ps. DFT calculations were carried out at the B3LYP/6-311G(d,p) level using the Gaussian 09 package.

CONTEXT: Benzene and other aromatic groups, as planar groups with [Formula: see text] electrons cloud, tend to form stacking interactions which have an important role in various chemical and biological processes. In order to have a better insight in the nature of these interactions, we have performed a fractal analysis on patterns of electron density and electrostatic potential for two benzenes in stacking interaction. The calculated fractal dimension follows the trend of the calculated interaction energy for the interplanar distances of 4.0 to 6.0 Å, which partially coincides with the strongest attractive stacking interactions. The fractal dimension vs. energy dependences were fitted with the logistic curve, and the fitting coefficient was 0.96 up to 1.00. METHODS: For the benzene stacking interaction energy, with a range of conformations and distances between two benzenes, DFT calculations at the B3LYP+D3/aug-cc-pVDZ level were performed with the TURBOMOLE software. The fractal analysis for electron density and electrostatic potential has been done by python scripting.

CONTEXT: BaTiO3 is one of the most important ferroelectric oxides in electronic applications. Also, it has attractive properties for catalysis that could be used for reducing contamination levels, especially carbon monoxide, CO. CO is one of the main gaseous pollutants generally released from the combustion of fossil fuel. In this work, the CO transformation on pristine and Au-modified BaTiO3 perovskite for H2CO obtention is studied. The CO adsorption and hydrogenation on pristine BaTiO3 leads to formaldehyde synthesis as the most stable product through two possible routes. Furthermore, hydrogenation stages are less probable on pristine BaTiO3. On Au-modified BaTiO3 formaldehyde is the principal product too but Au adatom generates H2CO competition with HCOH. After BaTiO3 modification with Au unpaired electrons were generated. These unpaired electrons are related to the adatom reactivity. According to the obtained results, pristine and Au-modified BaTiO3 can adsorb and hydrogenate CO generating formaldehyde as the principal product. BaTiO3 modifications with Au increase the reactivity of the perovskite in the CO hydrogenation reactions. CO hydrogenation process on Au suggests that further hydrogenation stages beyond formaldehyde are possible. METHODS: The study was performed through ab initio calculations using the periodic spin-polarized Density Functional Theory (DFT) as implemented in Quantum ESPRESSO. DFT calculations were carried out using the Plane Wave self-consistent field (PWscf). Spin density difference allows us to identify reactive regions related to dangling bonds and unpaired electrons. A plane wave basis set was used to represent the electron states. Vanderbilt pseudopotentials with nonlinear core correction were used to model the ionic cores and valence electrons interaction. Exchange-correlation energies were treated within the generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) parameterization.

CONTEXT: Pectin methylesterase inhibitor (PMEI) can specifically bind and inhibit the activity of pectin methylesterase (PME), which has been widely used in fruit and vegetable juice processing. However, the limited three-dimensional structure, unclear action mechanism, low thermal stability and biological activity of PMEI severely limited its application. In this work, molecular recognition and conformational changes of PME and PMEI were analyzed by various molecular simulation methods. Then suggestions were proposed for improving thermal stability and affinity maturation of PMEI through semi-rational design. METHODS: Phylogenetic trees of PME and PMEI were established using the Maximum likelihood (ML) method. The results show that PME and PMEI have good sequence and structure conservation in various plants, and the simulated data can be widely adopted. In this work, MD simulations were performed using AMBER20 package and ff14SB force field. Protein interaction analysis indicates that H-bonds, van der Waals forces, and the salt bridge formed of K224 with ID116 are the main driving forces for mutual molecular recognition of PME and PMEI. According to the analyses of free energy landscape (FEL), conformational cluster, and motion, the association with PMEI greatly disrupts PME's dispersed functional motion mode and biological function. By monitoring the changes of residue contact number and binding free energy, IG35M/ IG35R: IT93F and IT113W/ IT113W: ID116W mutations contribute to thermal stability and affinity maturation of the PME-PMEI complex system, respectively. This work reveals the interaction between PME and PMEI at the gene and protein levels and provides options for modifying specific PMEI.

CONTEXT: Metal-free heterogeneous materials have attracted great interest due to their potential to facilitate various organic transformations in line with circular economy and green chemistry principles. Among various 2D materials, graphene oxide (GO) is considered an attractive material for numerous applications in physics, chemistry, biology, material sciences, and catalysis. Furthermore, graphene-based catalysts exhibit good catalytic activity toward the selective oxidation of benzyl alcohol to benzaldehyde or benzoic acid under eco-friendly conditions. In this regard, a theoretical investigation was carried out to study both catalytic oxidation reaction pathways (i.e., benzyl alcohols to aldehyde and to benzoic acid) using GO as an eco-friendly and metal-free catalyst. METHODS: In this study, we report a theoretical investigation at the B3LYP/6-31G level to better understand the oxidation of benzyl alcohol using GO as a metal-free catalyst. The possible bond formation was investigated using the global and local reactivity indexes derived from Fukui functions. Furthermore, we performed a non-covalent interaction (NCI) analysis to unveil the stability and the interaction nature between both reagents and GO surface. The effect of the solvent on the oxidation efficiency was also performed and the results indicate that the solvent significantly affects the decrease of reactivity by increasing the activation barriers through oxidation reactions of benzyl alcohol. Additionally, the electron localization function (ELF) analysis was performed for all intermediates showing the ionic nature of the studied epoxide structure of GO and rules out any type of covalent interaction during the oxidation reaction of benzyl alcohol. All these obtained results are in good agreement with experimental observations and reveal that the epoxide functions on the graphene surface promote an excellent catalyst turnover.

CONTEXT: The co-adsorption of sulfate and metal ions on intrinsic and Al-doped graphene is investigated through first principles calculations. When SO42- ions exist only, both of intrinsic and Al-doped graphene can form stable adsorption configurations with SO42-. However, the presence of Cu2+/Ca2+/Zn2+/Mg2+ ions attenuates the interaction between intrinsic graphene and SO42-, resulting in weak physical adsorption between them, while Al-doped graphene can still constitute co-adsorption chemically with both SO42- and Cu2+/Ca2+/Zn2+/Mg2+ ions simultaneously. The sensitivity of Al-doped graphene towards co-adsorbed ions is in the order of SO42--Cu2+ > SO42--Zn2+ > SO42--Ca2+ > SO42--Mg2+. The research indicates Al-doped graphene could be a promising material for sensing sulfate ions under the presence of various metal ions. METHODS: All of the calculations were carried out by using a first principles method based on density functional theory (DFT). The generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) functional was selected to describe electron exchange-correlation energy. The double numerical plus polarization (DNP) was employed as the basis set. The conductor-like screening model (COSMO) was implemented to simulate the aqueous solvent effect.

CONTEXT: The [4 +2 ] cycloaddition reactions between furan and three substituted alkynes (5-R-substituted-3-(3-(phenylsulfonyl)-propioloyl)-oxazolidin-2-one) have been investigated using the MEDT approach. Reactivity indices, reaction pathways, and activation energies are calculated. In an investigation of conceptual DFT indices, furan acts as a nucleophile, while the three substituted alkynes (5-R-substituted-3-(3-(phenylsulfonyl)-propioloyl)-oxazolidin-2-one) function as electrophiles in this reaction. The cycloaddition is regioiselective, as demonstrated by the activation and reaction energies, in clear agreement with the experiment's results. Hetero Diels-Alder [4 + 2] cycloadditions occur following a non-concerted two stages one-step molecular mechanism. METHODS: For the purpose of this study, all calculations were performed using the Gaussian 09 software. Optimization was achieved through Berny's computational gradient optimization method, employing the B3LYP functional and the 6-31G(d) basis set. Analysis of both local and global reactivity indices provided insights into the reactivity tendencies of the reactants, distinguishing between electrophilic and nucleophilic characteristics via Parr functions. Frequency calculations were employed to identify and characterize stationary points, with transition states indicated by a single imaginary frequency and positive values of all frequencies for reactants and product. The electron localization function (ELF) was investigated using the Multiwfn software within the context of topological analyses.

CONTEXT: In recent years, semiempirical methods such as PM6, PM6-D3H4, and PM7 have been increasingly used for modeling proteins, in particular enzymes. These methods were designed for more general use, and consequently were not optimized for studying proteins. Because of this, various specific errors have been found that could potentially cast doubt on the validity of these methods for modeling phenomena of biochemical interest such as enzyme catalytic mechanisms and protein-ligand interactions. To correct these and other errors, a new method specifically designed for use in organic and biochemical modeling has been developed. METHODS: Two alterations were made to the procedures used in developing the earlier PMx methods. A minor change was made to the theoretical framework, which affected only the non-quantum theory interatomic interaction function, while the major change involved changing the training set for optimizing parameters, moving the focus to systems of biochemical significance. This involved both the selection of reference data and the weighting factors, i.e., the relative importance that the various data were given. As a result of this change of focus, the accuracy in prediction of heats of formation, hydrogen bonding, and geometric quantities relating to non-covalent interactions in proteins was improved significantly.

CONTEXT: Epidermal growth factor receptor (EGFR), a member of the HER receptor family, is over expressed in various cancer cells. Using tumor-specific antibodies to deliver cytotoxic agents directly to the tumor cells is an effective treatment strategy. Targeted therapy by fusing anti-EGFR scFv with tumor-specific cytokines promises the emergence of a new era. METHODS: We designed a novel immuno-apoptotic fusion protein, anti-EGFR scFv-IL-24, consisting of a specific cancer cell targeting antibody and recombinant cytokine IL-24 to explore its anti-cancerous potential. Amino acid sequences of both anti-EGFR scFv and IL-24 were fused using a specific rigid linker. In silico characterization of the designed fusion protein like to predict the primary, secondary, physiochemical properties, quality, and structural validation using online bioinformatic tools. The newly designed fusion protein consists of 402 amino acids that showed good quality with a predicted value of 76.7% having 81.5% residues in the most favored region as predicted by ERRAT2 and Ramachandran plot analysis. Docking and simulation studies were performed using HDOCK and Desmond module of Schrodinger. All the parameters of quality, validity, interaction analysis, and stability suggested that the fused molecule is fully operational and functional. The results of the study support that the anti-EGFR scFv-IL-24 fused protein could be proved as a novel candidate to combat cancer.

CONTEXT: The functionalization of graphene is the best way to improve its interfacial compatibility and dispersibility in polymer matrix to obtain high-performance composites. In this study, three nanocomposite models with different salt layer thicknesses were established and simulated by molecular dynamics method to understand the effect of oxygen-containing functional groups on the impermeability of epoxy coatings. Molecular dynamics (MD) simulation results show that the nanocomposites have better impermeability than pure epoxy resin. The thickness of salt solution affects the permeation rate of salt solution and the interfacial properties of nanocomposites. The salt solution molecules trapped in the coating are mainly concentrated at the interface between graphene and epoxy resin, which is the main reason for the decrease in interface properties of epoxy coating. METHODS: In this paper, Material Studio 8.0 was used to construct nanocomposite models with different salt layer thicknesses (GO/SW7Å, GO/SW10Å, and GO/SW13Å), and MD simulations were performed using a large-scale atomic and molecular parallel simulator (LAMMPS).

CONTEXT: Selecting high performance polymer materials for organic solar cells (OSCs) remains a compelling goal to improve device morphology, stability, and efficiency. To achieve these goals, machine learning has been reported as a powerful set of algorithms/techniques to solve complex problems and help/guide exploratory researchers to screen, map, and develop high performance materials. In present work, we have applied machine learning tools to screen data from reported studies and designed new polymer acceptor materials, respectively. Quantitative structure-activity relationship (QSAR) models were generated using machine learning-assisted simulation techniques. For this purpose, 3000 molecular descriptors are generated. Consequently, molecular descriptors having key effect on power conversion efficiency (PCE) were identified. Moreover, numerous regression models (e.g., random forest and bagging regressor models) were developed to predict the PCE. In particular, new materials were designed based on the similarity analysis. The GDB17 chemical database consisting of 166 million organic molecules in an ordered form is used for performing similarity analysis. A similarity behavior between GDB17 materials and the materials reported in literature is studied using RDKit (a cheminformatics software). Noteworthily, 100 monomers proved to be unique and effective, and PCEs of these monomers are predicted. Among these monomers, four monomers exhibited PCE higher than 14%, which is better than various reported studies. Our methodology provides a unique, time- and cost-efficient approach to screening and designing new polymers for OSCs using similarity analysis without revisiting the reported studies. METHODS: To perform machine learning analysis, data from reported studies and online databases was collected. Different molecular descriptors were generated for polymer materials utilizing Dragon software. 3D structures of studied molecules were applied as input (SDF; structure data file format). Importantly, about 3000 molecular descriptors were generated. Comma-separated value (.csv) file format was used to export these molecular descriptors. To shortlist best descriptors, univariate regression analysis was performed. These descriptors were further utilized for training machine learning models. Moreover, necessary packages of Python for data analysis and visualization were imported such as Matplotlib, Numpy, Pandas, Scikit-learn, Seaborn, and Scipy. Random forest and bagging regressor models were applied for performing machine learning analysis. A cheminformatics software, RDKit, was applied for similarity analysis.

CONTEXT: The investigation of the stability, electronic properties, and catalytic activity of clusters ConMoP holds significant applications and implications in catalyst design, materials science, energy conversion and storage, and environmental protection. The study aims to delve into the unique features of the clusters ConMoP(n = 1 ~ 5), aiming to drive advancements in these related fields. The results obtained from the analysis revealed the stable configurations of the ten clusters, primarily characterized by steric structures. Furthermore, the energy of the clusters was found to increase continuously during growth, as indicated by calculations of atomic fragmentation energy and atomic binding energy. The researchers conducted an analysis of the Natural Population Analysis(NPA) charge, which revealed that Co atoms acted as electron donors, while P and Mo atoms acted as electron acceptors within the clusters. Additionally, an examination of the electrostatic potential indicated that Co and Mo atoms displayed nucleophilic tendencies, while P atoms exhibited electrophilic characteristics. Moreover, the density of states curves, HOMO and LUMO orbitals, and Kooperman's theorem were applied to the clusters ConMoP(n = 1 ~ 5).Through this study, a deeper understanding of the properties and behavior of clusters ConMoP has been achieved, shedding light on their potential as catalysts. The findings contribute to the existing knowledge of these clusters and provide a basis for further research and exploration in this field. METHODS: In this study, we employed the clusters ConMoP(n = 1 ~ 5) to simulate the local structure of the material, enabling us to investigate the stability, electronic properties, and catalytic properties influenced by the metal atoms. By systematically increasing the number of metal atoms and expanding the cluster size, we explored the variations in these properties. Density functional theory (DFT) calculations were performed using the B3LYP hybrid functional implemented in the Gaussian09 software package. The clusters ConMoP(n = 1 ~ 5) underwent optimization calculations and vibrational analysis at the def2-tzvp quantization level, resulting in optimized configurations with different spin multiplet degrees. For data characterization and graphical representation of the stability, electronic properties, and catalytic properties of the optimized configurations, we utilized a range of computational tools. Specifically, the quantum chemistry software GaussView, wave function analysis software Multiwfn were employed. Through the comprehensive utilization of these computational tools, we gained valuable insights into the stability, electronic properties, and catalytic properties of the clusters ConMoP(n = 1 ~ 5) and their dependence on different metal atoms.

CONTEXT: Modulation of disease progression is frequently started by identifying biochemical pathway catalyzed by biomolecule that is prone to inhibition by small molecular weight ligands. Such ligands (leads) can be obtained from natural resources or synthetic libraries. However, de novo design based on fragments assembly and optimization is showing increasing success. Plasmodium falciparum parasite depends on glutathione-S-transferase (PfGST) in buffering oxidative heme as an approach to resist some antimalarials. Therefore, PfGST is considered an attractive target for drug development. In this research, fragment-based approaches were used to design molecules that can fit to glutathione (GSH) binding site (G-site) of PfGST. METHODS: The involved approaches build molecules from fragments that are either isosteric to GSH sub-moieties (ligand-based) or successfully docked to GSH binding sub-pockets (structure-based). Compared to reference GST inhibitor of S-hexyl GSH, ligands with improved rigidity, synthetic accessibility, and affinity to receptor were successfully designed. The method involves joining fragments to create ligands. The ligands were then explored using molecular docking, Cartesian coordinate's optimization, and simplified free energy determination as well as MD simulation and MMPBSA calculations. Several tools were used which include OPENEYE toolkit, Open Babel, Autodock Vina, Gromacs, and SwissParam server, and molecular mechanics force field of MMFF94 for optimization and CHARMM27 for MD simulation. In addition, in-house scripts written in Matlab were used to control fragments connection and automation of the tools.

CONTEXT: [3+2] cycloaddition processes between isoalantolactone (ISALL) and diazocyclopropane (DCYP), have been surveyed exercising the MEDT, reactivity indices, reactions, and activation energies, are computed. In an investigation of conceptual DFT indices, DCYP behaves as a nucleophile in this reaction, whereas ISALL acts as an electrophile. This cyclization is stereo-, chemo-, and regiospecific, as demonstrated by the activation and reaction energies, in clear agreement with the experiment's results. The mechanism for this [3+2] cycloaddition is occurring in two steps, according to ELF analysis. METHODS: For the purposes of this investigation, all computations were performed using the Gaussian 09 program. The optimization was completed using Berny's computational gradient optimization approach with the basis set 6-311G(d,p) and wB97XD functional. Frequency computations were utilized to characterize and locate stationary points where the transition phases have just one imaginary frequency and all frequencies for the reactants and products are positive. After evaluating the effect of dichloromethane (DCM) as a reaction solvent, the stationary point optimization was updated using the polarizable continuum model (PCM) developed by the Tomasi team. The electron localization function (ELF) has been examined within the context of topological investigations using Multiwfn software with a 0.05 grid step.

CONTEXT: Bisphenol A is an endocrine disruptor that may cause harmful effects on human health. Some residues of this compound have been found in water bodies, alerting for its possible risk as an environmental pollutant. Thus, this work proposes the use of pristine and oxidized phosphorene as removers of bisphenol A, through an adsorption mechanism. Our results indicate that the main interactions exhibited by the complexes are hydrogen bonds, van der Waals, and n-π stacking. All complexes show adsorption energies less than -1.08 eV for the gas phase, and -0.65 eV for the aqueous environment, suggesting that the models may be good capturers of this pollutant. According to the electronic properties, the systems are good donators/acceptors of charge; likewise, they are suitable to sense bisphenol A, because of their changes in |LUMO-HOMO| gap energy. The values obtained suggest that the number of oxygen atoms in the models is important for their adsorption capabilities; hence, the modulation in the oxidation is significant to enhance such properties. METHODOLOGY: Density functional theory calculations were implemented at the PBE-D3/TZVP level of theory in the ORCA 5.0 program, to evaluate the adsorption of bisphenol A on pristine and oxidized phosphorene models and propose the last as removers of this molecule. The visualization of the structures was done in the VMD code.

CONTEXT: Dihydroxylammonium 5,5'-biotetrazolium-1,1'-diolate (TKX-50) has two important properties of typical azole energy-containing ionic salts, including high energy and safety. Therefore, in today's era where more emphasis is placed on explosive performance and explosive detonation control conditions, TKX-50 is a very important object of research, and its reaction process in the initial stage of detonation is gradually receiving more and more attention from researchers in the field of energy-containing materials research. METHODS: In this paper, based on first-principles density-functional theory (DFT), the mechanism of chemical bond breakage of TKX-50 under pressure was determined based on the analysis of the strength and stability of chemical bonds inside the TKX-50 molecules using Raman spectroscopy relative intensity analysis. The results show that TKX-50 is dominated by N-H bond breaking and followed by H-O bond breaking in the initial reaction stage. These reactions lead to the reorganization and structural changes within the molecule, which eventually lead to the decomposition of TKX-50.

CONTEXT: The interaction between carbon nanostructures and heavy metal clusters is of great interest due to their potential applications as sensors and filters to remove the former from environment. In this work, we investigated the interaction between two types of carbon nanobelts (Möbius-type nanobelt and simple nanobelt) and nickel, cadmium, and lead nanoclusters. Our aim was to determine how both systems interact which would shed light on the potential applications of the carbon nanostructures as pollutant removal and detecting devices. METHODS: To investigate the interaction between carbon nanostructures and heavy metal nanoclusters, we utilized the semiempirical tight binding framework provided by xTB software with the GFN2-xTB Hamiltonian. We performed calculations to determine the best interaction site, lowest energy geometries, complexes stability (using molecular dynamics at 298K), binding energy, and electronic properties. We also carried out a topological study to investigate the nature and intensity of the bonds formed between the metal nanoclusters and the nanobelts. Our results demonstrate that heavy metal nanoclusters have a favorable binding affinity towards both nanobelts, with the Möbius-type nanobelt having a stronger interaction. Additionally, our calculations reveal that the nickel nanocluster has the lowest binding energy, displaying the greatest charge transfer with the nanobelts, which was nearly twice that of the cadmium and lead nanoclusters. Our combined results lead to the conclusion that the nickel nanoclusters are chemisorbed, whereas cadmium and lead nanoclusters are physisorbed in both nanobelts. These findings have significant implications for the development of sensor and filtering devices based on carbon and heavy metal nanoclusters.

CONTEXT: This article is an initiation to build reasonable atomic/molecular theory to study chemicals utilized in different sectors of science including chemistry, biology, and medicine as well as the material science. It is all about opening new pathways and method-developments which need to be simple, reasonable, rational, and applicable to all chemicals and be closely consistent with the experimental data and real world. Hence, the success may simplify the process and eliminate the need to sophisticated software and heavy computations. The article first reviews the current classical atomic theory, and discusses some of its flaws. Then, it suggests a more reasonable approach through several presented simple formulas which would generate results consistent with the experimental data. Finally, the article goes through some examples, cases, and details to present the differences between the new suggested approach and the current classical atomic theory. Building new pathways would help not only with the ongoing scientific achievements but it would also help in classrooms and the education of next future generations. METHODS: All of the calculations and figures presented in this article are done by simple calculators and the use of Microsoft software including excel spreadsheet. The presented atomic theory does not need any sophisticated software and/or heavy computations. If desired, one can also use a simple personal programing technique to generate the desired results. So the key is in better understanding of the subjects and not in development of complicated computational tools and theoretical techniques. This article did not use any of the usual ab initio or DFT, or basis sets, or force field molecular-dynamics techniques. The focus of this article is mainly atomic theory which will expand to molecular theory in future articles.

INTRODUCTION: First-principles calculations were used to study the adsorption behavior of environmentally significant gases CO, CO2, NO, NO2, SO, and SO2 on pure buckled aluminene (b-Al) for gas sensing applications. Therefore, structural, electronic, and adsorption properties including adsorption energy values and recovery time have been calculated and discussed. METHODS: All the structures were optimized using Amsterdam Density Functional (ADF) code BAND. In addition, triple zeta polarization basis with slater-type orbitals were utilized. RESULTS: For every gas analyzed, we observed favorable adsorption energy values and charge transfer occurring between the gas molecule and b-Al. In the valance band, there was a strong hybridization between the p orbitals of gas and b-Al, this led to enhanced conductivity in the density of states (DOS). The recovery time suggested that the adsorption of NO, NO2, SO, and SO2 gases on b-Al is good for the application of reversible gas sensors. The recovery time indicated that the b-Al material is very sensitive to NO, NO2, SO, and SO2 gas molecules. CONCLUSION: The conclusion in light of all these results is that b-Al based materials can appear as a probable candidate for high gas sensing performance.