The pharmacological potential of marine alkaloids is enormous due to their diverse bioactivities. In this work, we performed a comprehensive computational analysis of marine alkaloids, including Calcardine C, Ernstine A, Naamine H, Naamine I, Naamidine J, Naamidine K, Phorbatopsin D, and Phorbatopsin E, in connection with Mycothiol S-conjugate amidase (MycoSCoA), an essential enzyme for Mycobacterium tuberculosis metabolism. Frontier molecular orbital (FMO) analysis and geometry optimization show that Naamidine J is the most stable compound; its low HOMO–LUMO gaps suggest high reactivity. According to electrostatic potential mapping, naamidine K has the highest charge distribution, which is in line with a higher binding potential. The strong intramolecular charge transfer of the lead compounds was further confirmed by Natural Bond Orbital (NBO) analysis. Molecular docking studies show that Naamidine K and Naamidine J have the highest binding affinities with MycoSCoA (-10.6 and -9.3 kcal/mol, respectively). These substances use a range of hydrophobic and hydrogen bonding interactions to create stable complexes. It is noteworthy that Naamidine J exhibited superior binding to 4EWL (-9.3 kcal/mol), which was sustained by a network of hydrogen bonds and π-interactions. The selectivity of the marine alkaloids was highlighted by the weakest interactions, which were shown by BOG and GOL. This in silico study highlights Naamidine K and J as promising candidates for further anti-tuberculosis drug development in general.

Lithium-ion batteries (LIBs) have dominated the energy storage field due to their high energy density, long cycle life, and environmental friendliness. In this study, we systematically investigated the electrochemical properties of phosphorus (P)-doped γ-graphyne as a promising LIBs anode material using density functional theory calculations. The formation energy and cohesive energy of γ-graphyne at varying doping concentrations are calculated, demonstrating excellent experimental synthesizability of P-doped γ-graphyne. Notably, the P-doped system exhibits enhanced electrical conductivity compared to pristine γ-graphyne. The adsorption energy of a single lithium (Li) atom on P-doped γ-graphyne is determined to be -3.72 eV, significantly higher than those of N-doped, Si-doped, and intrinsic γ-graphyne. Even with increasing Li storage, the Li adsorption energy remains greater than the cohesive energy of bulk lithium, while the average open-circuit voltage falls within the optimal range of 0-1 V, ensuring high operational safety. Remarkably, the theoretical Li storage capacity of P-doped γ-graphyne reaches 1150.68 mAh/g, which is 1.85 times that of pristine γ-graphyne and 3.09 times that of conventional graphite. Furthermore, the diffusion barrier calculations reveal that P-doped γ-graphyne substantially reduces the Li-ion migration energy barrier, indicating favorable lithium diffusion kinetics. In summary, P-doped γ-graphyne demonstrates exceptional advantages in specific capacity, structural stability, electrical conductivity, and Li-ion diffusion kinetics, providing critical theoretical insights and experimental guidance for designing next-generation high-performance LIBs anode materials.

In this study, the protective gas Ar of lead bismuth eutectic (LBE) operating environment and the substances such as Po、Pb、Bi、Po 2、Bi 2、PbPo produced during LBE operation were divided into three-atom group (Po 2-Po、Po 2-Pb、Po 2-Bi、Bi 2-Po、Bi 2-Pb、Bi 2-Bi、PbPo-Po、PbPo-Pb、PbPo-Bi) and four-atom group (Po 2-Po 2、Po 2-Bi 2、Po 2-PbPo、Bi 2-Bi 2、Bi 2-PbPo、PbPo-PbPo). The intermolecular interaction potential of each component was calculated respectively, and the Lennard-Jones (L-J) parameters of each component were obtained according to the relevant formula. Based on these L-J parameters, the transport properties such as binary diffusion coefficient, viscosity coefficient and thermal conductivity at high temperature were calculated. The results show that the well depth of each component of the three-atom group is much greater than that of the four-atom group, which results in the binary diffusion coefficient of each component of the three-atom group is much smaller than that of the four-atom group. In addition, it was found that the viscosity coefficient and thermal conductivity of the same substance seemed to have a fixed ratio, so we calculated the Prandtl number of Po 2 and Bi 2, and compared them with the Prandtl number of substances such as air, water and argon, and found that the thermal conductivity of Po 2 and Bi 2 was better than that of water and argon, but slightly lower than that of air. Finally, we calculate the rate constant of reaction PbPo+Po→Po 2+Pb in the temperature range of 400 K~2000 K at standard pressure(1.0 bar).

We present a derivation of an ab intio model potential (AIMP) based on the Van Vleck Perturbation theory. We applied the derivation to the specific case of a molecular system made of one alkali atom interacting with rare gas atoms. Our approach provides a formal background for the empirical potential often used to study this kind of molecular systems and allows us to discuss their intrinsic limitations and some possible improvements. In particular, the use of AIMP, which keeps the nodal structure of the orbitals, allows us to take into account accurately the spin-orbit relativistic correction. Its application to alkali-rare gas diatomic molecules allows us to reproduce rather well the known experimental and the best ab initio calculations at a lower computational cost.

Small-molecule non-fullerene acceptors (SM-NFAs) featuring a three-dimensional and four-bladed propeller-like structure have gained attention due to their unique molecular framework as guest component in ternary organic solar cells (TOSCs). However, there is currently a scarcity of theoretical research into the photovoltaic properties of these SM-NFAs. This gap is especially pronounced when it comes to comprehending how modifications to their end groups (EGs) influence their electronic structures. In this work, SF-BTA1, SF-BTA2, and SF-BTA3 SM-NFA are selected since they have been experimentally synthesized and have different impacts on the performance of TOSCs. Using density functional theory (DFT) and time-dependent DFT (TDDFT), we have computed and analyzed their ground state and excited state properties, including molecular planarity, electrostatic potential maps and their corresponding fluctuations, dipole moments, frontier molecular orbitals, electron-hole distributions, UV-Vis absorption spectra, singlet-triplet energy gap difference (∆E ST), and exciton binding energy, as well as the open-circuit voltage of OSCs based on these four-bladed propeller-like molecules. The theoretical results align well with experimental data. Furthermore, as a guest acceptor, SF-BTA1 exhibits the smallest electrostatic potential fluctuations and singlet-triplet energy gap (∆E ST). This implies that these two factors could play crucial roles in evaluating whether a four-bladed propeller-like molecule is suitable to serve as an effective guest acceptor. Our results not only unveil the underlying mechanism about the roles of these NFAs in TOSCs but also provide valuable insights for the further design and optimization of highly efficient TOSCs.

Raman spectroscopy, when combined with Density Functional Theory (DFT) calculations, is a powerful method for investigating the vibrational properties of a broad range of molecular systems. When the Raman laser’s wavelength resonates with the molecule’s electronic transitions absorption, certain vibrational peaks are significantly amplified in the resulting spectrum. This effect, known as Resonance Raman (rR) spectroscopy, enhances the detection of molecular features and allows the observation of species at low concentrations. However, predicting rR spectra through DFT presents significant computational challenges. The theoretical modeling of rR spectra is more complex than non-resonant Raman spectra and less documented in the literature. This guide aims to address this gap by providing detailed and practical instructions for predicting rR spectra using various computational chemistry software, including ORCA, Gaussian, and ADF. The methods outlined are designed to help researchers accurately model rR spectra, providing deeper insights into molecular structure, reactivity, and chemical transformations.

LaTaON 2 is a promising visible-light-responsive photocatalyst for water splitting because of its broad visible light absorption and suitable band edge positions. However, the high defect concentration hinders the charge transfer and results in the poor photocatalytic performance of LaTaON 2. Loading proper cocatalysts is one of the most efficient strategies for promoting charge separation/transfer and achieving high reaction activity. In this work, we have used density functional theory calculations to study the depositions of Pt, Ru and Ni single atom cocatalysts on LaTaON 2(010) surface. The most stable adsorption configuration is the same site for all the elements, namely the top of the N atom on the La-terminated surface and the fourfold hollow site on the Ta-terminated surface. The adsorption of metal single atom on Ta-termination is stronger than that on La-termination due to the formation of more bonds. Upon the deposition, no localized impurity states appear in the middle of the forbidden gap since the n d states of metal adatoms are located within the valence band and conduction band of LaTaON 2. The efficiency of the photocatalysts is probed by investigating their ability to adsorb H atom in a thermodynamically manner. Our results reveal that the energetically favorable sites of HER are the N atom on the La-termination and the O and N atoms on the Ta-termination, respectively. Compared with the clean surface, the surfaces with Pt, Ru and Ni single adatoms exhibit higher performance for HER because loading metal cocatalysts can further activate the surface nonmetal atoms and reduce the Gibbs free energy of hydrogen adsorption. The work gives an atom-level insight into the role of metal single atom cocatalysts in LaTaON 2 photocatalyst for hydrogen production.

A comprehensive understanding of the interaction mechanisms between nitric acid and sugar is crucial for applying sugars as denitrifying agents in the treatment of high-level radioactive waste. However, the evolutionary behavior and interaction mechanisms of nitric acid with sugar remain unclear. In this work, the mechanisms and kinetics of the reaction between nitric acid and glucose that produce key products (NO 2, NO, CO 2, and CO) have been studied in detail by means of quantum chemistry. The work shows five different paths leading to the ring-opening of β-D-glucopyranose. The results indicate that the ring-opening path involving the interaction of H 3O + with glycosidic oxygen has the greatest kinetic advantage, with lower energy of highest point (EHP) (63.6 kJ/mol) and lower highest energy barrier (HEB) (49.2 kJ/mol). At the same time, the study shows that the redox reaction between nitric acid and the aldehyde group of glucose plays a dominant role throughout the reaction pathway. This process not only reduces nitric acid to nitrous acid, laying the foundation for the subsequent production of NO 2 and NO, but also oxidizes the aldehyde group to a carboxyl group, creating conditions favorable for the generation of CO 2 and CO. In addition, through thermodynamic analysis of the four reaction products (NO 2, NO, CO 2, and CO), the study shows that the reactions producing NO 2 and NO are spontaneous exothermic reactions, while the reactions generating CO 2 and CO are non-spontaneous endothermic reactions.

Developing novel non-fullerene acceptors (NFAs) by modifying A 1-DA 2D-A 1 Y6 molecules is an effective strategy to improve the energy conversion efficiency of organic solar cells (OSCs). To understand the mechanism of regulating the photovoltaic performance by modifying the central fused-ring, end-group and inner-chain segments of Y6, D18:Y6, D18:AQx-2, D18:AQx-18, D18:BTIC-γ-2CN and D18:Z9 OSCs were systematically studied based on extensive quantum chemistry calculations, and the impacts of different chemical groups on molecular properties and photovoltaic performances were analyzed. The substitution of benzothiadiazole in the central fused ring of Y6 with quinoxaline, substituting quinoxaline with phenazine, introducing benzonitriles at the end group and phenyl groups into inner side chains enhance molecular skeleton planarity, slightly elevate the highest occupied molecular orbital energy and the lowest excitation energy, and enlarge light absorption efficiency. Introducing quinoxaline and phenyl groups cause the reduction of electrostatic potential difference between D18 and NFAs, on the contrary, introducing phenazine and benzonitriles induce the opposite effects. Introducing quinoxaline and phenazine generate negligible effects on charge transfer (CT) energies, whereas introducing benzonitrile and the phenyl group increase CT energies. Introducing phenazine and phenyl group generate sufficient energy difference between local excitation and CT to conquer exciton binding. The rate constants calculated using Marcus theory indicate that all molecular modifications of Y6 reduced exciton dissociation rates. However, the introducing benzonitrile increase CT and suppress charge recombination rates. The results reveal the inherent relationship between molecular structure and photovoltaic performance, providing the theoretical basis for design and development of NFAs.

In the present study, a novel strategy for constructing new cage energetic compounds with both high energy and low sensitivity was proposed. That is to use a 3D nitrogen-rich cage compounds as the core parent molecule to set the basis for obtaining high energy, and followed by the introduction of a moderate number of nitro groups into the cage which be linked with the carbon atoms to further improve the energy without increasing the sensitivity obviously, and controlling the reaction difficulty caused by the too many nitro groups as low as possible. The amino groups were introduced into the structure also to adjust the balance of energy and sensitivity. Finally, more importantly, the formation of nitrogen-rich cage, and the introduction of nitro/amino groups were achieved synchronously by a typical and attractive one-step reaction (The Diels-Alder reaction) which possesses the 100% atomic efficiency. Based on this strategy, six series of amino-substituted nitrogen-rich azoles were used as the dienes, to react with different dienophiles like the tetranitroethylene (TNE) to form the final cage products. From the theoretical investigation results, five optimal compounds (PA0, PB0, PC0, PE0, PE1) with low reaction energy barrier (11.2 to 31.6 kcal/mol), and may set the high energy of CL-20 and low sensitivity of TNT together, have been screened out as new advanced energetic compounds successfully. This study may provide a new feasible strategy and a unique perspective for developing new advanced energetic compounds.

C4F7N with excellent insulation performance has been proposed to replace the traditional SF6 as a new insulating medium in power equipment. In the present study, the molecular structure and radiative efficiency (RE) of C4F7N are calculated and compared with SF6 based on DFT calculation. The decomposition of pure C4F7N and the basic interactions between C4F7N and hydroxyl radical in the constructed co-crystal of C4F7N-H2O have been simulated by applying Monte-Carlo calculation and Car-Parrinello molecular dynamics (CPMD) method, in order to obtain reasonable and full-scale atmospheric dissociation processes. Then the detailed decomposition pathways are learned with DFT method of M062X. The rate constants of different pathways are further applied for calculating the atmosphere lifetime of C4F7N, to evaluate the possibility of applying it as an alternative gas of SF6 in power equipment. All the atmospheric chemical behaviours are determined by electronic structure and reflected by the decomposition pathways of C4F7N with interacting with hydroxyl radicals. Rather than traditional hypothesizing reaction models, this study provides a reasonable and practicable method to evaluate more alternative protective gas for understand the greenhouse effect.

In this work, we propose a technique for the use of fermionic neural networks (FermiNets) with the Slater exponential Ansatz for electron-nuclear and electron-electron distances, which provides faster convergence of target ground-state energies due to a better description of the interparticle interaction in the vicinities of the coalescence points. Our analysis of learning curves indicates on the possibility to obtain accurate energies with smaller batch sizes using arguments of the bagging approach. In order to obtain even more accurate results for the ground-state energies, we propose an extrapolation scheme for estimating Monte Carlo integrals in the limit of an infinite number of points. Numerical tests for a set of molecules demonstrate a good agreement with the results of the original FermiNets approach (achieved with larger batch sizes than required by our approach) and with results of the coupled-cluster singles and doubles with perturbative triples (CCSD(T)) method that are calculated in the complete basis set (CBS) limit.

Experimental and theoretical studies show that two-dimensional (2D) materials have great potential applications in the fields of optoelectronics, semiconductors and spintronic devices. Based on the First Principles, the stability, band structure, electronic properties and optical properties of hydrogenated C3B, a new graphene like two-dimensional (2D) material, are studied in this paper. The results show that: firstly, with the increase of hydrogenation degree, the sp2 orbital hybridization in C3B structure gradually transits to a more stable sp3 mode, and the valence band energy near the Fermi level decreases; Secondly, adsorbed H atoms can regulate the bandgap of C3B. When the number of adsorbed H is even, C3B structure behaves as a semiconductor, and meanwhile the bandgap increases. When H atoms is odd, C3B is easy to show metallicity; Finally, the main absorption peak of the optical absorption spectrum decreases first and then increases with the increase of H concentration. The law of the secondary absorption peak is opposite to the main peak. When the ratio of hydrogenation is 50%, an obvious secondary absorption peak appears. This study confirms that hydrogenation is an effective way to regulate the electronic properties of materials, which can expand the application of 2D material C3B in optoelectronic devices.

A proper benchmarking on the properties of HF and its dimer inside C60 using density functional theory (DFT) based approaches is presented. For this purpose, 10 different DFT functionals following Jacob’s Ladder have been chosen. Geometrical parameters, viz., bond length, bond angle, etc., and dipole moment have been computed. Two types of orientations, viz., L-shaped and anti-parallel of (HF)2 inside C60 are considered, the latter with an extremely short hydrogen bond. HF bond lengths are elongated upon encapsulation in comparison to its free state analogue. The calculated stability of HF@C60 is functional dependent whereas, (HF)2C60 is thermodynamically unstable for all the functionals. The kinetic stability of (HF)2@C60 is observed through ADMP simulation at 300K temperature. The red shift in HF stretching frequencies is noticed in all cases. NCI analysis exhibits a non-covalent type interaction between HF dimer and the C60 cage. The total interaction energy is found to be negative for HF@C60. EDA analysis showed a high value of repulsive ΔEpauli which makes the (HF)2@C60 system unstable except for the functional BP86-D3 of GGA family. Furthermore, QTAIM analysis is performed and confirmed the presence of (3, -1) bond critical point along the hydrogen bond region for L-shaped (HF)2C60.

In this account we report an implementation of the quantum trajectory-guided adaptive Gaussian (QTAG) method in a modular open-source Libra package for quantum dynamics calculations. The QTAG method is based on a representation of wavefunctions in terms of a quantum trajectory-guided adaptable Gaussians basis and is generalized for time-propagation on multiple coupled surfaces to be applicable to model nonadiabatic dynamics. The potential matrix elements are evaluated within either the local harmonic or bra-ket-average (linear) approximations to the potential energy surfaces, the latter being a more practical option. Performance of the QTAG method is demonstrated and discussed for the Holstein and Tully models, which are the standard benchmarks for method development in the area of nonadiabatic dynamics.

Density functional theory (DFT) was used to calculate the most stable structures of Gen (n=2-5) clusters as well as the adsorption energies of Gen (n=2-5) clusters after adsorbing single water molecule. The calculation of the reaction paths between Gen (n=2-5) and single water molecule shows that water molecule can react with Gen (n=2-5) clusters to dissociate to produce hydrogen, and O atoms mix with the clusters to generate GenO (n=2-5). According to the energy change of the reactions, the Ge2 cluster is the most efficient among Gen (n=2-5) clusters reacting with single water molecule. The NPA and DOS respectively proved that the Ge atoms in the product don’t reach the highest valence, and it was jointly predicted that GenO (n=2-5) might continue to react with more water molecules. Our findings contribute to better knowledge of Ge’s chemical reactivity, which could aid in the development of effective Ge-based catalysts and hydrogen-production methods.

In this study, the improved Tietz potential was used to describe the internal vibration of a diatomic molecule. With the help of the expression for bound state energy levels, a more generalized equation for the upper bound vibrational quantum number and canonical partition function were obtained for the diatomic system. The obtained partition function was used to derive analytical equation for the prediction of constant pressure (isobaric) molar heat capacity of diatomic molecules. The analytical model was used to predict the constant pressure molar heat capacity data of the ground state CO, BBr, HBr, HI, P2, KBr, Br2, PBr, SiO and Cl2 molecules. The upper bound vibrational quantum number obtained for the molecules are 85, 100, 21, 21, 115, 301, 89, 157, 110 and 67. The computed average absolute deviation are 2.3462%, 1.1342%, 2.3350%, 1.9078%, 0.7268%, 2.4041%, 1.7849%, 1.8989%, 2.5209% and 2.1523%. The present results are in good agreement with available literature data on gaseous molecules.

Understanding the surface chemistry of nanostructured TiO2 has long been a priority to improve photochemical device efficiency. Faceted nanoparticles, characterized by known facets not at thermodynamically ideal ratios, are particularly challenging to model due to the large number of chemical and computational parameters that must be chosen for which there is no experimental guidance. This research supplies a modeling framework for faceted TiO2 nanoparticles that provides rationale for such decisions. By performing full DFT optimization and characterization on a series of inter-related anatase TiO2 nanoparticles displaying {101}, (001), and {010} facets with sizes up to 202 TiO2 units, parameter space is mapped with regard to particle size, shape, defects, and optimization protocol. Specifically, it is shown that pre-optimization is necessary in order to achieve a sufficiently delocalized electronic structure, and the increased reorganization afforded by removing higher coordinated Ti atoms compensates the high formation energy of creating these defects. Furthermore, by characterizing differently shaped nanoparticles with the same number of TiO2 units, this research provides direct observation of shape effects on nanoparticles.