Computational Chemistry Calculations Research Articles

WebMO: Web‐based computational chemistry calculations in education and research

AbstractWebMO is a web‐based interface for all major quantum chemistry programs. WebMO uses a server–client architecture that installs on a single server or cluster computer and provides access to state‐of‐the‐art computational chemistry programs from a standard web browser. The web interface provides a 3‐D molecular editor, pre‐defined calculations types, job submission and monitoring, visualization of results, and user management tools. Barriers to using state‐of‐the‐art computational chemistry in teaching and research are minimized through WebMO's universal accessibility, its intuitive and uniform interface to all programs, no software to install on client computers, and support for multiple users with a single instance. Applications of WebMO throughout the undergraduate curriculum are provided. The extensible open‐architecture design allows for collaboration among educators, researchers, quantum chemistry program developers, and the WebMO interface developers.This article is categorized under: Computer and Information Science > Visualization Electronic Structure Theory > Ab Initio Electronic Structure Methods Software > Quantum Chemistry

Ceratonia Siliqua L seeds extract as eco-friendly corrosion inhibitor for carbon steel in 1 M HCl: Characterization, electrochemical, surface analysis, and theoretical studies

Electrochemical and theoretical behaviors of the carbon steel was investigated in 1 M HCl solution using the Ceratonia Siliqua L seeds (CFE) extract. This extract was analyzed using GC–MS technique; it was found that the extract contains 18 compounds on which the main constituents represent 27.78 wt.% vanillin (VN), 25.69 wt.% α-tumerone (AT), 11.68 wt.% 2-heptanal (HP), 9.49 wt.% mome-inositol (MI), 4.94 wt.% 1-dotiacontanol(DT), and 2.92 wt.% linoleic acid (LA). The corrosion inhibition and adsorption (CIA) behavior were investigated using the electrochemical measurements (open circuit potential (OCP), polarization curves (PC) and impedance spectroscopy (IS)), and both thermodynamic and kinetic parameters (ΔHa, ΔSa and Ea). The outcomes show that CFE extract exhibits a worthy anti-corrosion action with an inhibition efficiency (η%) of 95% at 100 mg/l at 298 °K. This result could be attributed probably to the adsorption of CFE extract matrix on carbon steel surface, and this was confirmed by surface visualization using SEM-EDS technique. The adsorption of CFE extract onto carbon steel surface is controlled by a Langmuir adsorption isotherm, which suggests that there are no interactions between molecules of the CFE during adsorption. The computational chemistry calculations by density functional theory (DFT), natural bond orbital (NBO), molecular electrostatic potential surface (MESP) and Metropolis Monte Carlo (MC) methods were performed to better understand the inhibition and adsorption behavior of the main constituents of CFE extract on the Fe (110) surface.

Triazole based copper(II) complexes: Synthesis, spectroscopic characterization, Density Function Theory study, and biomimicking of copper containing oxidase proteins

AbstractWithin the framework of the present study, a polydentate ligand with S and N donor sites along with its CuII‐based chelates were prepared and characterized. Elemental and thermal analyses, μeff and ΛM measurements as well as spectroscopy techniques including FT‐IR, electronic spectra, and EPR are the characterization tools. Computational chemistry calculations were applied to confirm the geometrical assignments of the penta and hexa coordinated perchlorato and chloro derivatives, respectively. Octahedral and trigonal bipyramidal stereochemistries were assigned for these copper(II) chelates. Powder X‐ray spectroscopy data were processed by Expo 2014 computer program for the structural illustration of one of the existing octahedral metal complexes. Biomimicking of copper(II) containing proteins phenoxazinone synthase and catechol oxidase was studied and the obtained results demonstrated promising oxidase‐like activity of the present CuII‐base complexes. Kinetic measurements were also performed to identify the potential catalytic pathways of the studied oxidation processes. The type of the counter‐anion included in the complexes significantly controls the structural features and the catalytic properties.

Conformational behavior of naphtho-merocyanine dimers on Au(111)

Thin film growth of molecules on substrates are governed by the convolution of inter-molecular forces and template-adsorbate interactions. Often the initial dimer formation plays a crucial role in the outcome of the molecular structure on the surface. Here, the behavior of naphtho-merocyanine on an Au(111) substrate was investigated using computational chemistry methods and Scanning Tunneling Microscopy. The experiments show a strong preference of dimer formation of the merocyanine molecules. Topographical measurements are used to identify two distinguished configurations, an elongated/oval dimer and a compact/rectangular dimer. With the addition of computational chemistry calculations including Density Functional Theory (DFT) and Molecular Mechanics calculations using the AMBER 3 force field, these two configurations of two specific merocyanine conformers, namely CTC and CTT, could be identified. Intermolecular binding energy calculations could be performed. This is a first step in understanding the possible island/thin film growth of naphtho-merocyanine and subsequently possible pathways toward the switching behavior of merocyanine and spiropyran on this substrate.

The Study of Stability and Structure of the Interaction Between β-Carotene Compounds with Methanol, Ethanol, Acetone, Chloroform, Carbon Tetrachloride, Cyclohexane, and N-Hexane using the Hartree-Fock and the Density Functional Theory Method

The purpose of this study was to determine the stability and structure on the interaction between β-carotene compounds with methanol, ethanol, acetone, chloroform, carbon tetrachloride, cyclohexane, and n-hexane compounds. This research is a molecular modeling using computational chemistry calculations with the function/basis set RHF/3-21G and B3LYP/3-21G. The computational chemistry calculations used Gaussian 09 Revision D 01 and visualization used the Jmol and Avogadro software. The data obtained from computational chemistry calculations with the function/basis set RHF/3-21G on the interaction between β-carotene -methanol compounds are ΔE = -11.899 kJ / mol, β-carotene -ethanol ΔE = -12.256 kJ/mol, β-carotene -acetone ΔE = -9.276 kJ/mol, β-carotene -chloroform ΔE = 5.262 kJ/mol, β-carotene -carbon tetrachloride ΔE = 3.747 kJ/mol, β-carotene-cyclohexane ΔE = 2.691 kJ/mol, β-carotene-n-hexane ΔE = 6.453 kJ/mol. The data obtained with the function/basis set B3LYP/3-21G on the interaction between β-carotene-methanol compounds are ΔE = -24.588 kJ/mol, β-carotene -ethanol ΔE = -25.123 kJ/mol, β-carotene -acetone ΔE = -18.140 kJ/mol, β-carotene -chloroform ΔE = 2.255kJ/mol, β-carotene -carbon tetrachloride ΔE = -1.187 kJ/mol, β-carotene-cyclohexane ΔE = -0.801 kJ/mol, β-carotene -hexane ΔE = -0.412 kJ/mol. Based on the analysis of thermodynamic data from computational chemistry calculations with the function / basis set UHF/3-21G and B3LYP/3-21G, it was found that β-carotene-ethanol and β-carotene-methanol mixtures had very stable mixtures.

Purification of hypocrellins from Shiraia bambusicola by coordinated high-speed countercurrent chromatography using cupric chloride as a complexing agent.

Hypocrellins are anthraquinone that can act as excellent photosensitizers for photodynamic therapy. In the present work, we found that high-speed countercurrent chromatography using cupric chloride as a complexing agent effectively separated hypocrellins from Shiraia bambusicola extract. The optimal two-phase solvent system consisted of petroleum ether/ethyl acetate/methanol/water (7:3:5.5:4.5, v/v/v/v), with 0.01mol/L cupric chloride in the lower phase at pH of 2.45. This lower phase served as the mobile phase, whereas the upper phase acted as the stationary phase. Employing a continuous separation mode, three continuous injections were found to allow the purification of 1.2g of crude extract in approximately 12 h. Hypocrellin B (10.8mg), hypocrellin A (16.2mg), and hypocrellin C (15.6mg) were obtained from this process. Simulation of complexation of hypocrellin A with divalent copper ion by computational chemistry calculations indicated that three pairs of hydroxyl and carbonyl groups in hypocrellin A had similar binding energies, and demonstrated that hypocrellin A and B owned different metal-to-ligand ratios as compared to hypocrellin C. These factors could modify the partitioning of these compounds in two-phase solvent system, and resulting in a suitable separation factor. This method would also be used to purify other anthraquinones from natural products.

Optimized Programs and Methods Required for the Computational Study of Beta Blockers

This study was designed to estimate the optimized conditions for the computational study of quantum characteristics of beta blockers. Carvedilol was selected as a representative of beta blockers. Optimized energies and bonds lengths were measured using different methods including PM3, HF and DFT. A comparison has been made between Gaussian and GAMESS programs. The difference in optimized energy values, and the a pproaching of the bonds angle to the optimal values were studied. The results showed that Gaussian software showed higher priority than GAMEES software, which can be obbserved from the differences in the optimized energy values and the approaching of the bonds angles to the optimal values. the obtained results will bedepeneded in all subscuent studies. IR spectroscopic data were employed to select the most appropriate method. three different methods (PM3, HF and DFT) have been used to measure IR, then compared with experimental values of carvedilol. DFT method showed an advantage over the other methodsBased on all above, DFT (B3LYP/6-311G) has been recommended in the computational chemistry calculations study for carvedilol and resemble beta blockers.

Impact of Aaronsohnia pubescens Essential Oil to Prevent Against the Corrosion of Mild Steel in 1.0 M HCl: Experimental and Computational Modeling Studies

The essential oil obtained from the aerial parts of Aaronsohnia pubescens plant (AP oil) was extracted by hydrodistillation, and then, its composition was analyzed by gas chromatography (GC) and GC-mass spectrometry (GC/MS). The corrosion inhibition and adsorption performance of the AP oil on the corrosion mild steel in 1 M hydrochloric acid was evaluated by weight loss analysis, electrochemical methods both stationary [Potentiodynamic polarization (PDP)] and transient [Electrochemical impedance spectroscopy (EIS)]. The weight loss outcomes indicate that AP oil shows a worthy inhibitory efficiency of 83.22% reached at 1.5 g L−1 and 343 K. The charge transfer process mainly controls the results of EIS measurements; PDP measurements showed that the studied AP oil performs as a mixed-type inhibitor. Furthermore, the adsorption on the steel is made according to the Langmuir model. The computational chemistry calculations by density functional theory, the electrostatic potential surface and Metropolis Monte Carlo methods were performed to acquire a greater understanding of adsorption mechanism for each compound among the third major compounds of AP oil on the Fe (110) surface. The finding results exhibited that the E-anethole will be considered as the best inhibitor against mild steel corrosion.

ACE2 coding variants in different populations and their potential impact on SARS-CoV-2 binding affinity

The susceptibility of different populations to SARS-CoV-2 infection is not yet understood. Here, we combined ACE2 coding variants' analysis in different populations and computational chemistry calculations to probe the effects on SARS-CoV-2/ACE2 interaction. ACE2-K26R; which is most frequent in Ashkenazi Jewish population decreased the SARS-CoV-2/ACE2 electrostatic attraction. On the contrary, ACE2-I468V, R219C, K341R, D206G, G211R increased the electrostatic attraction; ordered by binding strength from weakest to strongest. The aforementioned variants are most frequent in East Asian, South Asian, African and African American, European, European and South Asian populations, respectively.

Mechanisms of Solid–Gas Reactions: Reduction of Air Pollutants on Carbons

Ozone is a strong oxidizer and sulfur dioxide is a precursor to acid rain, both are air pollutants that can damage the respiratory tissues of animals and plants making them hazardous to the environment. They are isoelectronic valence O = X = O (X = S, O) molecules and their mechanism of reduction on carbons is similar. The solid–gas kinetics were studied in a flow system with a tubular reactor under differential and steady state conditions. Initial rates and product distribution were used to determine the stoichiometry of the reaction. The reduction of XO2 on carbons proceeds through a common primary mechanism with oxidized and reduced intermediates. The reactivity of the intermediates that were inserted on carbons (graphite, activated carbon, graphene oxide) modified by SO2 is selective with respect to aminolysis and thiolysis. A theoretical study of the chemisorption of SO2 on dehydrogenated pyrene as graphite active site model showed that at 900 °C the chemisorption occurs mainly on the diradical zigzag edge. Computational quantum chemistry calculations were carried out for the reduction of SO2 on graphite to produce elemental sulfur and CO2 using tetradehydrogenated-benzo[α]anthracene (TBA) as model. The mechanisms of the decarboxylation and sulfur transport steps were postulated. Ozonation of graphite showed that the 1,2,3-trioxolane decomposes to an oxyrene, eliminating O2. Both reactions, the SO2 and O3 with graphite, have the same experimental free energy of activation for the decarboxylation reaction. The results show that for SO2 the desulfurization has a much lower energetic demand than the decarboxylation route raising the important possibility of using the reaction of reduction of SO2 on carbons to reduce the acid rain, producing elemental sulfur as the main product, without increasing the greenhouse effect due to the formation of CO2.

Distinct binding of cetirizine enantiomers to human serum albumin and the human histamine receptor H1.

Cetirizine, a major metabolite of hydroxyzine, became a marketed second-generation H1 antihistamine that is orally active and has a rapid onset of action, long duration of effects and a very good safety record at recommended doses. The approved drug is a racemic mixture of (S)-cetirizine and (R)-cetirizine, the latter being the levorotary enantiomer that also exists in the market as a third-generation, non-sedating and highly selective antihistamine. Both enantiomers bind tightly to the human histamine H1 receptor (hH1R) and behave as inverse agonists but the affinity and residence time of (R)-cetirizine are greater than those of (S)-cetirizine. In blood plasma, cetirizine exists in the zwitterionic form and more than 90% of the circulating drug is bound to human serum albumin (HSA), which acts as an inactive reservoir. Independent X-ray crystallographic work has solved the structure of the hH1R:doxepin complex and has identified two drug-binding sites for cetirizine on equine serum albumin (ESA). Given this background, we decided to model a membrane-embedded hH1R in complex with either (R)- or (S)-cetirizine and also the complexes of both ESA and HSA with these two enantiomeric drugs to analyze possible differences in binding modes between enantiomers and also among targets. The ensuing molecular dynamics simulations in explicit solvent and additional computational chemistry calculations provided structural and energetic information about all of these complexes that is normally beyond current experimental possibilities. Overall, we found very good agreement between our binding energy estimates and extant biochemical and pharmacological evidence. A much higher degree of solvent exposure in the cetirizine-binding site(s) of HSA and ESA relative to the more occluded orthosteric binding site in hH1R is translated into larger positional fluctuations and considerably lower affinities for these two nonspecific targets. Whereas it is demonstrated that the two known pockets in ESA provide enough stability for cetirizine binding, only one such site does so in HSA due to a number of amino acid replacements. At the histamine-binding site in hH1R, the distinct interactions established between the phenyl and chlorophenyl moieties of the two enantiomers with the amino acids lining up the pocket and between their free carboxylates and Lys179 in the second extracellular loop account for the improved pharmacological profile of (R)-cetirizine.

Glycerol as Alternative Co-Solvent for Water Extraction of Polyphenols from Carménère Pomace: Hot Pressurized Liquid Extraction and Computational Chemistry Calculations.

Glycerol is a co-solvent for water extraction that has been shown to be highly effective for obtaining polyphenol extracts under atmospheric conditions. However, its efficacy under subcritical conditions has not yet been studied. We assessed different water-glycerol mixtures (15%, 32.5%, and 50%) in a hot pressurized liquid extraction system (HPLE: 10 MPa) at 90 °C, 120 °C, and 150 °C to obtain extracts of low molecular weight polyphenols from Carménère grape pomace. Under the same extraction conditions, glycerol as a co-solvent achieved significantly higher yields in polyphenols than ethanol. Optimal extraction conditions were 150 °C, with 32.5% glycerol for flavonols and 50% for flavanols, stilbenes, and phenolic acids. Considering gallic acid as a model molecule, computational chemistry calculations were applied to explain some unusual extraction outcomes. Furthermore, glycerol, methanol, ethanol, and ethylene glycol were studied to establish an incipient structure–property relationship. The high extraction yields of gallic acid obtained with water and glycerol solvent mixtures can be explained not only by the additional hydrogen bonds between glycerol and gallic acid as compared with the other alcohols, but also because the third hydroxyl group allows the formation of a three-centered hydrogen bond, which intensifies the strongest glycerol and gallic acid hydrogen bond. The above occurs both in neutral and deprotonated gallic acid. Consequently, glycerol confers to the extraction solvent a higher solvation energy of polyphenols than ethanol.

Geometry optimization using Gaussian process regression in internal coordinate systems.

Locating the minimum energy structure of molecules, typically referred to as geometry optimization, is one of the first steps of any computational chemistry calculation. Earlier research was mostly dedicated to finding convenient sets of molecule-specific coordinates for a suitable representation of the potential energy surface, where a faster convergence toward the minimum structure can be achieved. More recent approaches, on the other hand, are based on various machine learning techniques and seem to revert to Cartesian coordinates instead for practical reasons. We show that the combination of Gaussian process regression with those coordinate systems employed by state-of-the-art geometry optimizers can significantly improve the performance of this powerful machine learning technique. This is demonstrated on a benchmark set of 30 small covalently bonded molecules.

Removal of Cr (VI) from an aqueous solution using an activated carbon obtained from teakwood sawdust: Kinetics, equilibrium, and density functional theory calculations

Because of its acute toxicity and high mobility, the hexavalent chromium [Cr (VI)] found in wastewater is a risk to the environment. In this study, activated carbon was produced from teakwood sawdust, which was chemically modified using ZnCl2 (AT) as an efficient adsorbent for Cr (VI) removal from aqueous systems. Batch experiments were conducted to identify kinetic, diffusional, and equilibrium parameters. In addition, to better understand the adsorption process, computer calculations were conducted based on the density functional theory (DFT). A maximum adsorption capacity of 72.46 mg g−1 was achieved by adapting experimental data to the Langmuir isotherm model. Intraparticle diffusion was further identified through a three-dimensional diffusion model, which revealed that it was ruled by intraparticular diffusion based on surface diffusion, with surface diffusion coefficient (Ds) values ranging from 1.29 × 10−10 to 0.78 × 10−10 cm2 s−1. Finally, computational chemistry calculations and an FTIR analysis determined that oxygenated functional groups, lactone, semiquinone, phenols, and carboxylic acids were involved in the process of Cr (VI) adsorption on AT. Moreover, the main adsorption mechanisms were found to be complexation, electrostatic interaction, and reduction of Cr (VI) to Cr (III).

Reduction of 1,2,3-trichloropropane (TCP): pathways and mechanisms from computational chemistry calculations.

The characteristic pathway for degradation of halogenated aliphatic compounds in groundwater or other environments with relatively anoxic and/or reducing conditions is reductive dechlorination. For 1,2-dihalocarbons, reductive dechlorination can include hydrogenolysis and dehydrohalogenation, the relative significance of which depends on various structural and energetic factors. To better understand how these factors influence the degradation rates and products of the lesser halogenated hydrocarbons (in contrast to the widely studied per-halogenated hydrocarbons, like trichloroethylene and carbon tetrachloride), density functional theory calculations were performed to compare all of the possible pathways for reduction and elimination of 1,2,3-trichloropropane (TCP). The results showed that free energies of each species and reaction step are similar for all levels of theory, although B3LYP differed from the others. In all cases, the reaction coordinate diagrams suggest that β-elimination of TCP to allyl chloride followed by hydrogenolysis to propene is the thermodynamically favored pathway. This result is consistent with experimental results obtained using TCP, 1,2-dichloropropane, and 1,3-dichloropropane in batch experiments with zerovalent zinc (Zn0, ZVI) as a reductant.

Polarization consistent basis sets using the projector augmented wave method: a renovation brought by PAW into Gaussian basis sets.

A recently introduced framework incorporating the Projector Augmented Wave method and Gauss-type function (GTF-PAW) [X.-G. Xiong and T. Yanai, J. Chem. Theory Comput., 2017, 13, 3236-3249] opens alternative possibilities for performing low-cost molecular computational chemistry calculations. In this work, we present our first attempt to expand the applicability of this method by developing a family of compact general contracted polarization consistent basis sets (PAW-Ln) as an optimized GTF basis in combination with PAW. The results show that PAW-Ln, despite having small numbers of primitives, can provide not only better performance than effective core potential (ECP) but also good accuracy and desirable systematic convergence compared to larger all-electron basis sets. This demonstrates that GTF-PAW using the PAW-Ln basis sets could be a better alternative to both conventional all-electron- and ECP-based approaches for routine DFT calculations.

Crystal structure, Hirshfeld surface analysis and inter-action energy and DFT studies of 1-methyl-3-(prop-2-yn-1-yl)-2,3-di-hydro-1H-1,3-benzo-diazol-2-one.

In the title mol-ecule, C11H10N2O, the di-hydro-benzimidazol-2-one moiety is essentially planar, with the prop-2-yn-1-yl substituent rotated well out of this plane. In the crystal, C-HMthy⋯π(ring) inter-actions and C-HProp⋯ODhyr (Mthy = methyl, Prop = prop-2-yn-1-yl and Dhyr = di-hydro) hydrogen bonds form corrugated layers parallel to (10), which are associated through additional C-HBnz⋯ODhyr (Bnz = benzene) hydrogen bonds and head-to-tail, slipped, π-stacking [centroid-to-centroid distance = 3.7712 (7) Å] inter-actions between di-hydro-benzimidazol-2-one moieties. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (44.1%), H⋯C/C⋯H (33.5%) and O⋯H/H⋯O (13.4%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry calculations indicate that in the crystal, C-H⋯O hydrogen-bond energies are 46.8 and 32.5 (for C-HProp⋯ODhyr) and 20.2 (for C-HBnz⋯ODhyr) kJ mol-1. Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Studying the Effect of Temperature on the Formation of Hydrogen Bond Dimers: A FTIR and Computational Chemistry Lab for Undergraduate Students

This laboratory experiment allows one to study the effect of temperature in the process of formation of hydrogen bound cyclic dimers of benzoic acid (BA). The implementation of the proposed methodology, which comprises the use of FTIR spectroscopy and quantum chemistry calculations, enables the obtaining of the thermodynamic parameters of the dimerization reaction and their subsequent validation by computational chemistry calculations. Hence, the students are involved in a practical learning scheme focused in the study of a central topic in chemistry, such as hydrogen bonding, with the final purpose being to train chemistry students in applying theoretical-experimental approaches to extract meaningful data and valuable information for explaining experimental observables.

Crystal structure, Hirshfeld surface analysis and inter-action energy and DFT studies of 3-{(2Z)-2-[(2,4-di-chloro-phen-yl)methyl-idene]-3-oxo-3,4-di-hydro-2H-1,4-benzo-thia-zin-4-yl}propane-nitrile.

The title compound, C18H12Cl2N2OS, consists of a di-hydro-benzo-thia-zine unit linked by a -CH group to a 2,4-di-chloro-phenyl substituent, and to a propane-nitrile unit is folded along the S⋯N axis and adopts a flattened-boat conformation. The propane-nitrile moiety is nearly perpendicular to the mean plane of the di-hydro-benzo-thia-zine unit. In the crystal, C-HBnz⋯NPrpnit and C-HPrpnit⋯OThz (Bnz = benzene, Prpnit = propane-nitrile and Thz = thia-zine) hydrogen bonds link the mol-ecules into inversion dimers, enclosing R 2 2(16) and R 2 2(12) ring motifs, which are linked into stepped ribbons extending along [110]. The ribbons are linked in pairs by complementary C=O⋯Cl inter-actions. π-π contacts between the benzene and phenyl rings, [centroid-centroid distance = 3.974 (1) Å] may further stabilize the structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (23.4%), H⋯Cl/Cl⋯H (19.5%), H⋯C/C⋯H (13.5%), H⋯N/N⋯H (13.3%), C⋯C (10.4%) and H⋯O/O⋯H (5.1%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry calculations indicate that the two independent C-HBnz⋯NPrpnit and C-HPrpnit⋯OThz hydrogen bonds in the crystal impart about the same energy (ca 43 kJ mol-1). Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

The Role of Electrolyte Additives on the Stability and Electrochemical Performance of Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) are attractive owing to their high theoretical energy density (2600 Wh kg-1)1, low cost, and natural abundance. However, a major drawback of LSBs is an uncontrolled lithium dendrite formation during cycling leading to serious safety issue, low Coulombic efficiency and poor cycle performance. To overcome this drawback, electrolyte additives are typically used to control the lithium dendrite growth by chemically forming stable solid-electrolyte interphase (SEI) above the metallic Li anode. The SEI layers are formed via several steps with rather complex mechanisms2. To elucidate the mechanisms of SEI formation, in this work, many electrolyte additives with different anions (e.g., LiNO3, LiClO4, LiBr, LiI, LiBF4) have been investigated using computational chemistry calculations along with the experimental study to gain fundamental understanding. The different additives exhibit different reaction pathways with LiTFSI to form the decomposed products over lithium surface and directly correlate to the evolution of LiF. This affects the cell performance in terms of the coulombic efficiency and capacity retention. For example, the LiNO3 provides the highest efficiency while it gives poor capacity retention. LiClO4 can provide high capacity retention over cycling. We believe that this work will provide the understanding of the effect of the additives that can enhance overall performance and safety of lithium-sulfur batteries. REFERENCES Chen, L.; Shaw, L. L. J. Power Sources 2014, 267, 770-783.Lili, W.; Yusheng, Y.; Nan, C.; Yongxin, H.; Li, L.; Feng, W.; Renjie, C. Adv. Funct. Mater. 2018, 0 (0), 1800919. Figure 1