Molecular Dynamics Calculations Research Articles

Temperature-dependent iron motion in extremophile rubredoxins – no need for ‘corresponding states’

Extremophile organisms are known that can metabolize at temperatures down to − 25 °C (psychrophiles) and up to 122 °C (hyperthermophiles). Understanding viability under extreme conditions is relevant for human health, biotechnological applications, and our search for life elsewhere in the universe. Information about the stability and dynamics of proteins under environmental extremes is an important factor in this regard. Here we compare the dynamics of small Fe-S proteins – rubredoxins – from psychrophilic and hyperthermophilic microorganisms, using three different nuclear techniques as well as molecular dynamics calculations to quantify motion at the Fe site. The theory of ‘corresponding states’ posits that homologous proteins from different extremophiles have comparable flexibilities at the optimum growth temperatures of their respective organisms. Although ‘corresponding states’ would predict greater flexibility for rubredoxins that operate at low temperatures, we find that from 4 to 300 K, the dynamics of the Fe sites in these homologous proteins are essentially equivalent.

Application of the Hybrid Model to EHL Reference Liquids for Pressure Extrapolation

Reference liquids can be useful in the new quantitative approach to elastohydrodynamic lubrication calculations only if the properties of these liquids are accurately modeled. The pressures in the contact sometimes exceed the pressures of the available viscometer measurements, requiring extrapolation. The previtreous piezoviscous response is always faster-than-exponential with an apparent divergence pressure. Therefore, any model used for extrapolation must possess these characteristics and up to now published work in EHL, where extrapolation of the viscosity of squalane is performed, has not. To date, the only model that has been shown to accurately extrapolate to high pressure is the Hybrid model. This expression was applied to six reference liquids for use in quantitative investigations in EHL. Viscosity measurements for trioctyl trimellitate were extended to 1.1 GPa. The results obtained with high pressure viscometers are preferable over molecular dynamics results if they are different. Molecular dynamics calculations are not currently capable of reliable results for viscosity at very high pressures.

Rational Design of the Spatial Effect in a Fe(II)/α‐Ketoglutarate‐Dependent Dioxygenase Reverses the Regioselectivity of C(sp3)‐H Bond Hydroxylation in Aliphatic Amino Acids

The hydroxylation of remote C(sp3)‐H bonds in aliphatic amino acids yields crucial precursors for the synthesis of high‐value compounds. However, accurate regulation of the regioselectivity of remote C(sp3)‐H bonds hydroxylation in aliphatic amino acids continues to be a common challenge in chemosynthesis and biosynthesis. In this study, the Fe(II)/α‐ketoglutarate‐dependent dioxygenase from Bacillus subtilis (BlAH) was mined and found to catalyze hydroxylation at the γ and δ sites of aliphatic amino acids. Through crystal structure analysis, molecular dynamic simulation and quantum chemical calculations revealed that regioselectivity was regulated by the spatial effect of BlAH. Based on this result, the spatial effect of BlAH was reconstructed to stabilize the transition state at the δ site of aliphatic amino acids, thereby successfully reversing the γ site regioselectivity to the δ site. For example, the regioselectivity of L‐Homoleucine (5a) was reversed from the γ site (1:12) to the δ site (>99:1). The present study not only expands the toolbox of biocatalysts for the regioselective functionalization of remote C(sp3)‐H bonds, but also provides a theoretical guidance for the precision‐driven modification of similarly remote C(sp3)‐H bonds in complex molecules.

A density functional theory study of hydrogen storage on Ni and Pd doped hetero GeC nanotubes

AbstractUsing ab‐initio DFT based simulations, the hydrogen storage capacity of transition metal (TM = Ni, Pd) decorated doped germanium carbide nanotubes (GeCNTs) with heteroatoms (B, N, Ga, and As) has been examined. The study reveals that each Ni atom bonded on GeCB, GeCN, GeCGa, and GeCAs can attach at the most of 3H2, 2H2, 4H2, and 5H2 molecules with an average binding energy of −.36, −.40, −.32, and −.37 eV/H2, respectively. When doped GeCNTs are fully decorated with Ni atoms, their gravimetric hydrogen storage capacities are around 4.05, 2.73, 5.38, and 6.57 wt%, respectively. The desorption temperature of the systems is 460, 511, 404, and 473 K, respectively. When doped GeCNTs are fully decorated with Pd atoms, their gravimetric hydrogen storage capacities are around 2.07, 3.07, 4.05, and 3.07 wt%, respectively. These findings demonstrate that doped‐GeC adorned with Pd does not satisfy US DOE hydrogen storage requirements. The molecular dynamic (MD) calculations are utilized to examine the stability of the considered structures. The results demonstrate that Ni‐adorned GeCAs are a suitable material for hydrogen storage, which will motivate scientists to fabricate GeCAs‐based fuel cell devices.

Evolution of the Electrical Conductivity of LiNb1−xTaxO3 Solid Solutions across the Ferroelectric Phase Transformation

The investigation of the structural phase transition in the vicinity of the Curie temperature of crystals is motivated by the expected combination of advantageous high‐temperature properties of and , including high piezoelectric modules and remarkable high‐temperature stability, respectively. marks the ultimate limit for exploiting the piezoelectric properties; however, transition‐related structural modifications might impact this and other properties even below . Remarkably, the phase transition from the ferroelectric to the paraelectric phase, whose temperature strongly depends on the composition x, shows a significant drop in the activation energy of the electrical conductivity. The magnitude, temperature dependence, and underlying mechanisms of this drop are discussed from a microscopic perspective. Molecular dynamics calculations in the framework of the density functional theory show that substantial displacements of the cations occur below for both the end compounds and , and might thus affect the electrical conductivity. Above , the migration of lithium ions is presumably facilitated by a shortened diffusion path for the most favorable jump of the lithium ions. Electronic contributions to the conductivity, which become important above 900 K, are explained within the polaronic picture by the formation and migration of free small polarons.

Mechanistic insights into the role of cyclodextrin in the regioselective radical CH trifluoromethylation of aromatic compounds.

The regioselective radical CH trifluoromethylation of aromatic compounds have been shown to proceed in good yield and high regioselectivity when cyclodextrin (CD) is present. Yet, the reaction mechanism and the role of CD during the reaction have remained obscure. To this end, here we performed density functional theory (DFT) calculations to the conformations obtained by semiempirical quantum mechanical molecular dynamics calculations to reveal the reaction mechanism and the role of CD in controlling regioselectivity. The results show that metal salt increases the yield but do not affect the regioselectivity, which we further confirmed by an experiment. In contrast, multiple CD-substrate complex conformations and reaction pathways were obtained, and CD was shown to contribute to improving the regioselectivity by stabilizing the intermediate state via encapsulation. The present study indicates that CDs can increase the regioselectivity by stabilizing the intermediate and product states while only marginally affecting the transition state.

Experimental and dynamic molecular study of zinc extraction from sphalerite concentrate in ternary deep eutectic solvent

The utilization of deep eutectic solvents (DESs) as a novel class of solvents in metal production offers a promising alternative to aqueous solutions due to their biocompatibility and non-aqueous nature. This study investigated the leaching of sphalerite concentrate using a ternary stable DES composed of choline chloride (ChCl), p-toluene sulfonic acid (PTSA), and ethylene glycol (EG) (at a molar ratio of 1:1:1). The effects of time, temperature, and milling time on zinc recovery were examined within specific ranges (20–1440 min, 40–100 °C, and 0–24 h, respectively). The study revealed the significant influence of time and temperature on zinc dissolution efficiency within ChCl:PTSA:EG. Higher temperatures and longer leaching times were found to improve efficiency substantially. The research emphasized the crucial role of milling time, demonstrating that longer durations enhanced zinc efficiency by introducing more defects on the sphalerite surface and reducing particle size. Under optimized conditions, including a temperature of 100 °C, 24 h of ball milling, and 1440 min of leaching, a zinc recovery of 99.7% was achieved. Infrared analysis confirmed the chemical stability of the solvents during the leaching process. The sphalerite leaching process involved the formation of zinc chloride ion complexes and evolution H2S gas. An unexpected finding is the presence of lead sulfate in the leach residue, which may be attributed to sulfide oxidation to sulfate species. The Avrami kinetic model provided an excellent fit with the sphalerite dissolution data in ChCl:PTSA:EG DES, indicating that the rate-controlling step was primarily influenced by the diffusion process. R2 values for kinetics fitting data were in the range of 0.87–0.97 for temperature of 40–100 °C. The molecular dynamic (MD) simulation findings indicated robust electrostatic interactions between the metal ions Zn2+ and Fe2+ and the Cl− ions of the ChCl molecules. Additionally, the MD calculations showed that the metal ions formed complexes with some O-S-O atoms within the PTSA molecule.

Expression analysis and mapping of Viral—Host Protein interactions of Poxviridae suggests a lead candidate molecule targeting Mpox

BackgroundMonkeypox (Mpox) is an important human pathogen without etiological treatment. A viral-host interactome study may advance our understanding of molecular pathogenesis and lead to the discovery of suitable therapeutic targets.MethodsGEO Expression datasets characterizing mRNA profile changes in different host responses to poxviruses were analyzed for shared pathway identification, and then, the Protein–protein interaction (PPI) maps were built. The viral gene expression datasets of Monkeypox virus (MPXV) and Vaccinia virus (VACV) were used to identify the significant viral genes and further investigated for their binding to the library of targeting molecules.ResultsInfection with MPXV interferes with various cellular pathways, including interleukin and MAPK signaling. While most host differentially expressed genes (DEGs) are predominantly downregulated upon infection, marked enrichments in histone modifiers and immune-related genes were observed. PPI analysis revealed a set of novel virus-specific protein interactions for the genes in the above functional clusters. The viral DEGs exhibited variable expression patterns in three studied cell types: primary human monocytes, primary human fibroblast, and HeLa, resulting in 118 commonly deregulated proteins. Poxvirus proteins C6R derived protein K7 and K7R of MPXV and VACV were prioritized as targets for potential therapeutic interventions based on their histone-regulating and immunosuppressive properties. In the computational docking and Molecular Dynamics (MD) experiments, these proteins were shown to bind the candidate small molecule S3I-201, which was further prioritized for lead development.ResultsMPXV circumvents cellular antiviral defenses by engaging histone modification and immune evasion strategies. C6R-derived protein K7 binding candidate molecule S3I-201 is a priority promising candidate for treating Mpox.

Achieving High-Performance Lithium-Sulfur Batteries by Modulating Li+ Desolvation Barrier with Liquid Crystal Polymers.

Lithium-sulfur (Li-S) batteries offer high theoretical capacity but are hindered by poor rate capability and cycling stability due to sluggish Li2S precipitation kinetics. Here a sulfonate-group-rich liquid crystal polymer (poly-2,2'-disulfonyl-4,4'-benzidine terephthalamide, PBDT) is designed and fabricated to accelerate Li2S precipitation by promoting the desolvation of Li+ from electrolyte. PBDT-modified separators are employed to assemble Li-S batteries, which deliver a remarkable rate capacity (761 mAh g-1 at 4 C) and cycling stability (500 cycles with an average decay rate of 0.088% per cycle at 0.5 C). A PBDT-based pouch cell even delivers an exceptional capacity of ≈1400 mAh g-1 and an areal capacity of ≈11 mAh cm-2 under lean-electrolyte and high-sulfur-loading condition, demonstrating promise for practical applications. Results of Raman spectra, molecular dynamic (MD) and density functional theory (DFT) calculations reveal that the abundant anionic sulfonate groups of PBDT aid in Li+ desolvation by attenuating Li+-solvent interactions and lowering the desolvation energy barrier. Plus, the polysulfide adsorption/catalysis is also excluded via electrostatic repulsion. This work elucidates the critical impact of Li+ desolvation on Li-S batteries and provides a new design direction for advanced Li-S batteries.

Computational design, docking, and molecular dynamics simulation study of RNA helicase inhibitors of dengue virus.

RNA viruses are complex pathogens in terms of their genetic makeup, mutation frequency, and transmission modes. They contain the RNA helicase enzyme, which plays a crucial role in the viral genome replication process. This work aims to develop and screen a potential molecule that could function as a dengue virus (DENV) RNA helicase inhibitor. The present study was performed by taking 26 potential derivatives of gedunin phytochemicals from the PubChem database as ligands. The binding study of the compounds were analyzed by in silico docking method considering DENV RNA helicase enzyme as the receptor. After a thorough analysis of the docking scores, toxicity, and physicochemical properties, compound tetrahydrogedunin was obtained as the best. Based on tetrahydrogedunin molecular structure, 100 drug-like molecules were designed using the Data Warrior tool. After the screening process for drug-likeness and ADMET properties, the derivative number 42 was considered as the promising. Further comparative docking of derivative 42 and a standard inhibitor molecule ST-610 with DENV RNA helicase enzyme showed binding affinity as -10.0 kcal/mol and -9.6 kcal/mol, respectively. The favorable interaction between DENV RNA helicase and derivative 42 was further validated by 50 nanoseconds molecular dynamics simulation and MM-GBSA analysis. Since the antiviral activity of derivative 42 has not been reported till date, the compound was predicted as a novel therapeutic molecule that can act against the dengue virus (DENV) RNA helicase enzyme.

A new dynamic Monte Carlo method satisfying n-particle diffusion equation with position-dependent diffusion coefficient, free energy, and intermolecular interactions.

A dynamic Monte Carlo (MC) method recently proposed by us [Nagai et al., J. Chem. Phys. 156, 154506 (2022)] to describe single-particle diffusion of a molecule in a heterogeneous space with position-dependent diffusion coefficient and free energy is generalized here to n-particle dynamics, where n molecules diffuse in heterogeneous media interacting via their intermolecular potential. Starting from the master equation, we give an algebraic proof that the dynamic MC transition probabilities proposed here produce particle trajectories that satisfy the n-particle diffusion equation with position-dependent diffusion coefficient D0i(ri), free energy F1i(ri), and intermolecular interactions Vij(ri, rj). The MC calculations based on this method are compared to molecular dynamics (MD) calculations for two-dimensional heterogeneous Lennard-Jones test systems, showing excellent agreement of the long-distance global diffusion coefficient between the two cases. Thus, the particle trajectories produced by the present MC transition probabilities satisfy the n-particle diffusion equation, and the diffusion equation well describes the long-distance trajectories produced by the MD calculations. The method is also an extension of the conventional equilibrium Metropolis MC calculation for homogeneous systems with a constant diffusion coefficient to the dynamics in heterogeneous systems with a position-dependent diffusion coefficient and potential. In the present method, interactions and dynamics of the real systems are coarse-grained such that the calculation cost is drastically reduced. This provides an approach for the investigation of particle dynamics in very complex and large systems, where the diffusing length is of sub-micrometer order and the diffusion time is of the order of milliseconds or more.

Molecular dynamics exploration of the temperature-dependent elastic, mechanical, and anisotropic properties of hcp ruthenium

Molecular dynamics calculations were performed for the hitherto unclarified temperature-dependent elastic, mechanical, and anisotropic properties of the hexagonal closed pack (hcp) ruthenium (Ru) between 0 and 1200 K. All elastic stiffness constants were found to decrease with increasing temperature. Under the examined temperature range, hcp Ru obeys Born stability conditions. Further, both Pugh ratio analyses and calculated Poisson ratio values mutually suggest the brittle character of hcp Ru between 0 and 1200 K. The intricate hardness behavior of hcp Ru was also obtained and discussed throughout the work. For the considered temperature range, hcp Ru exhibits apparent elastic anisotropy that exponentially increases with increasing temperature. Moreover, presently obtained ground state (T = 0 K and P = 0 GPa) theoretical data for hcp Ru agree well with the former experimental and theoretical data. The present findings on the temperature-dependent characteristics of this metal may further inspire future applied works.Graphical abstract

Defect Engineering for Enhanced Electrocatalytic Oxygen Reaction on Transition Metal Oxides: The Role of Metal Defects.

Metal defect engineering is a highly effective strategy for addressing the prevalent high overpotential issues associated with transition metal oxides functioning as dual-function commercial oxygen reduction reaction/oxygen evolution reaction catalysts for increasing their activity and stability. However, the high formation energy of metal defects poses a challenge to the development of strategies to precisely control the selectivity during metal defect formation. Here, density functional theory calculations are used to demonstrate that altering the pathway of metal defect formation releases metal atoms as metal chlorides, which effectively reduces the formation energy of defects. The metal defects on the monometallic metal oxide surface (Mn, Fe, Co, and Ni) are selectively produced using chlorine plasma. The characterization and density functional theory calculations reveal that catalytic activity is enhanced owing to electronic delocalization induced by metal defects, which reduces the theoretical overpotential. Notably, ab initio molecular dynamics calculations, ex situ XPS, and in situ ATR-SEIRAS suggest that metal defects effectively improve the adsorption of reactive species on active sites and enhance the efficiency of product desorption, thereby boosting catalytic performance.

Effect of three-stage heat treatment on mechanical properties and micro-deformation mechanism of TC4 titanium alloy welded joint

The influence of three-stage heat treatment on the microstructure and mechanical properties of pulsed laser-arc hybrid welded TC4 titanium alloy joints was studied by experiments and molecular dynamics calculations. The results showed that after the three-stage heat treatment, a large number of fine and diffusely distributed secondary α phases were found in the welded joint, which increased the content of the phase boundary. The TEM characterization and calculation results show that the phase boundary had a strong hindering effect on the dislocation slip. As a result, under three-stage heat treatment conditions, the hardness of the welded joint was increased by 50%, and the yield strength and tensile strength of the welded joints were increased by 24.3% and 13.9%, respectively. The impact toughness of the base metal significantly improved after heat treatment, which was 31.6% higher than that before heat treatment due to the increase in the equiaxed α phase from the weld metal to the base metal. A large number of stacking faults were generated during the tensile deformation of the welded joint before heat treatment due to the low stacking fault energy of the α phase, which could effectively release the stress and hinder the dislocation slip. After heat treatment, the stacking fault of the welded joint decreased owing to the obvious increase in stacking fault energy. The micro-cracks propagated rapidly along the lamellar α phase to fracture. Therefore, the plasticity of the welded joint decreased, although the strength was improved after heat treatment.

Synaptic vesicle protein 2A mitigates parthanatos via apoptosis-inducing factor in a rat model of pharmacoresistant epilepsy.

Synaptic vesicle protein 2A (SV2A) is a unique therapeutic target for pharmacoresistant epilepsy (PRE). As seizure-induced neuronal programmed death, parthanatos was rarely reported in PRE. Apoptosis-inducing factor (AIF), which has been implicated in parthanatos, shares a common cytoprotective function with SV2A. We aimed to investigate whether parthanatos participates in PRE and is mitigated by SV2A via AIF. An intraperitoneal injection of lithium chloride-pilocarpine was used to establish an epileptic rat model, and phenytoin and phenobarbital sodium were utilized to select PRE and pharmacosensitive rats. The expression of SV2A was manipulated via lentivirus delivery into the hippocampus. Video surveillance was used to assess epileptic ethology. Biochemical tests were employed to test hippocampal tissues following a successful SV2A infection. Molecular dynamic calculations were used to simulate the interaction between SV2A and AIF. Parthanatos core index, PARP1, PAR, nuclear AIF and MIF, γ-H2AX, and TUNEL staining were all increased in PRE. SV2A is bound to AIF to form a stable complex, successfully inhibiting AIF and MIF nuclear translocation and parthanatos and consequently mitigating spontaneous recurrent seizures in PRE. Moreover, parthanatos deteriorated after the SV2A reduction. SV2A protected hippocampal neurons and mitigated epileptic seizures by inhibiting parthanatos via binding to AIF in PRE.

Facet and energy predictions in grain boundaries: Lattice matching and molecular dynamics

Many material properties can be traced back to properties of their grain boundaries. Grain boundary energy (GBE), as a result, is a key quantity of interest in the analysis and modeling of microstructure. A standard method for calculating grain boundary energy is molecular dynamics (MD); however, on-the-fly MD calculations are not tenable due to the extensive computational time required. Lattice matching (LM) is a reduced-order method for estimating GBE quickly; however, it has only been tested against a relatively limited set of data, and does not have a suitable means for assessing error. In this work, we use the recently published dataset of Homer et al. (2022) to assess the performance of LM over the full range of GB space, and to equip LM with a metric for error estimation. LM is used to generate energy estimates, along with predictions of facet morphology, for each of the 7,304 boundaries in the Homer dataset. The relative and absolute error of LM, based on the reported MD data, was found to be 5%–8%. An essential part of the LM method is the faceting relaxation, which corrects the expected energy by convexification across the compact space (S2) of boundary plane orientations. The original Homer dataset did not allow for faceting, but upon extended annealing, it was shown that facet patterns similar to those predicted by LM emerged.

Phloretin Prolongs Lifespan of Caenorhabditis elegans via Inhibition of NDUFS1 and NDUFS6 at Mitochondrial Complex Ⅰ

Phloretin has been widely perceived as an antioxidant. However, the bioavailability of phloretin in vivo is generally far too low to elicit a direct antioxidant effect by scavenging reactive oxygen species (ROS). Here we showed that administration of phloretin of apple polyphenols extended lifespan of Caenorhabditis elegans and promoted fitness. Specially phloretin enhanced the survival rates of nematodes under oxidants in an inverted U-shaped dose-response manner. The lifespan-extending effects of phloretin were mediated by ROS via complex I inhibition. The increase of ROS stimulated p38 MAPK/PMK-1 as well as transcription factors of NRF2/SKN-1 and FOXO/DAF-16. Consistent with the involvement of NRF2/SKN-1 and FOXO/DAF-16 in lifespan-extending effects, activities of SOD and CAT were enhanced by phloretin. The exogenous application of antioxidants BHA and NAC abolished the increase of ROS, the enhancement of SOD and CAT activities, and the lifespan extending effects of phloretin. Meanwhile, with the inhibition of mitochondrial complex I, ATP was instantly decreased. Both energy sensors of AMPK/AAK-2 and SIRT1/SIR-2.1 were involved in the lifespan extension by phloretin. Transcriptomic, real-time qPCR and molecular docking analyses demonstrated that the binding of phloretin at complex I located at NDUFS1/NUO-5, NDUFS2/GAS-1, and NDUFS6/NDUF-6. The molecular dynamic simulation and binding free energy calculations showed that phloretin had high binding affinities towards NDUFS1 (-7.21 kcal/mol) and NDUFS6 (-7.02 kcal/mol). Collectively, our findings suggested phloretin had effects of life expectancy enhancement and fitness promotion via redox regulations in vivo. NDUFS1/NUO-5 and NDUFS6/NDUF-6 might be new targets in the lifespan and wellness regulations.

Semimetallic state transition in Two-Dimensional carbon nitride covalent networks and enhanced electrocatalytic activity for nitrate to ammonia conversion

Single-atom catalysts (SACs), due to their maximum atomic utilization rate, show tremendous potential for application in the electrocatalytic synthesis of ammonia from nitrate. Yet, the development of superior supports that preserve the high selectivity, activity, and stability of SACs remains an imperative challenge. In this work, based on first-principles calculations and tight-binding (TB) model analysis, a new two-dimensional (2D) carbon nitride monolayer, C7N6, is proposed. The C7N6 structure exhibits a strong covalent network, with dynamical, thermal, and mechanical stability. Surprisingly, the structural transition from C9N4 to C7N6 corresponds to a semimetallic state transition. Further symmetry analysis unveils that the Dirac states in C7N6 are protected by space–time inversion symmetry, and the physical origin of the Dirac cone was confirmed using the TB model. Additionally, a non-zero Z2 invariant and significant topological edge states demonstrate its topologically nontrivial nature. Considering the excellent structural and topological properties of C7N6, a three-step screening strategy is designed to identify eligible SACs for electrochemical nitrate reduction reaction (NO3RR), and Ti@C7N6 is identified as possessing the best activity, with the last proton-electron coupling step *NH2→*NH3 being the potential-determining step (PDS), for which the limiting potential is 0.48 V. Moreover, a free energy diagram shows that the *NOH reaction pathway is energetically preferred on Ti@C7N6, and ab initio molecular dynamics (AIMD) calculations at 500 K confirm its good thermal stability. Our study not only provides excellent CN-based support material but also offers theoretical guidance for constructing highly active and selective SACs for nitrate reduction.

Theoretical investigation of gas sensing properties of a monolayer gallenene: First-principles insight

Two dimensional (2D) materials exhibit potential to be used in thin film electronic devices. In present paper, we explore 2D polymorphs of α-Ga by performing ab−initio calculations based on density functional theory. Phonon calculations show that Ga100 and Ga010 planes are dynamically stable at 6% and 2% bi-axial tensile strain. The ab-inito molecular dynamics calculations show that while Ga100 plane retain structural stability in a free standing state for temperature up to 500 K, Ga010 plane shows structure distortion which further increases with increase in temperature. We find total energy of Ga010 plane is smaller (−1.09 eV/f.u.) than Ga100 plane, indicating that Ga010 plane is energetically more stable. We next follow the adsorption of toxic gas molecule over Ga010 plane, referred as gallenene sheet. The negative adsorption energy shows that adsorption of phosgene (CCl2O), hydrogen cyanide (HCN), phosphine (PH3), and hydrogen selenide (H2Se) gas molecule over gallenene sheet is feasible. We find that (CCl2O) H2Se gas (weakly) strongly interact with gallenene with adsorption energy of (−0.39 eV) −0.52 eV. Bader charge calculation shows transfer of electronic charge between adsorbed gas molecule and gallenene sheet, which further confirmed by plot of electron localization function (ELF). The recovery time of desorption for CCl2O (PH3) gas comes 3.90×10−6 s (2.85×10−4 s) due to greater (smaller) out of plane distance of 2.93 Å (2.75 Å). The current–voltage (I-V) characteristic shows small deviation due to lower concentration of gases over gallenene, which further confirmed by transmission spectra. We hope that our theoretical predictions will help experimentalists to synthesize gallenene based gas sensors.

Elucidating the role of polar functional groups in fluorinated polymer artificial interphase for stable lithium anodes

The properties of solid electrolyte interphase (SEI) are pivotal for stable lithium (Li) metal anodes. However, the process of formation and ion transport behavior of lithium fluoride (LiF) through the polar groups of organic fluorinated artificial SEI has not been clearly elucidated. Herein we demonstrate that the key role of polar functional groups in fluorinated polymer artificial SEI (FPASEI) is elucidated by using 2,2,2-trifluoroethylacrylate (TFEA) through radical polymerization. Density functional theory and ab initio molecular dynamics calculations demonstrate that the abundant CO polar groups in TFEA contribute a large number of electrons, thereby facilitating the degradation kinetics of CF bond cleavage in lithium bis(trifluoromethanesulfonyl)imide salt to yield LiF. Moreover, the presence of CF, COC, and CO groups in TFEA facilitate the migration of Li+ towards interchain regions through cation-dipole interaction, leading to dendrite-free Li deposition. The implementation of FPASEI in a Li||Li cell results in 500 h of Li plating/stripping cycling at 1 mA cm−2 and retains a capacity retention rate of 80 % after 265 cycles in Li||LiNi0.8Co0.1Mn0.1O2 cell. This study not only emphasizes the critical role of polar groups in artificial SEI but also presents a promising strategy for achieving stable Li metal batteries.