Journal of Chemical Physics最新文献_第9页

Low-energy dissociative recombination of OH. 氢氧根的低能解离重组。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0261887

J Forer, D Hvizdoš, C H Greene, V Kokoouline

引用次数: 0

Quadrupolar NMR relaxation as a local probe of collective dynamics in aqueous alkaline and alkaline-earth chloride solutions. 四极核磁共振弛豫作为碱水和碱土氯化物溶液集体动力学的局部探针。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0263974

Matthieu Wolf, Iurii Chubak, Benjamin Rotenberg

{"title":"Quadrupolar NMR relaxation as a local probe of collective dynamics in aqueous alkaline and alkaline-earth chloride solutions.","authors":"Matthieu Wolf, Iurii Chubak, Benjamin Rotenberg","doi":"10.1063/5.0263974","DOIUrl":"https://doi.org/10.1063/5.0263974","url":null,"abstract":"While nuclear magnetic resonance (NMR) provides valuable insights into the local environment of many nuclei, the unambiguous interpretation of the signal in terms of microscopic dynamics is often difficult, particularly when the quadrupolar relaxation mechanism comes into play. Here, we investigate the quadrupolar NMR relaxation of cations and anions in aqueous alkaline and alkaline-earth chloride solutions across a broad range of salt concentrations. Using a combination of density functional theory calculations and classical molecular dynamics simulations, we compute the electric field gradient (EFG) fluctuations over the relevant time scales. Predicted NMR relaxation rates are in good agreement with experiments from the literature. As previously reported for NaCl, we find that the increase in relaxation rate with salt concentration is primarily driven by the slowing of EFG fluctuations, while changes in the static variance of the EFG play a minor role. We highlight some specific features for smaller and divalent cations compared to the other monovalent ones. In addition, we assess the relevance of the Stokes-Einstein-Debye model, frequently used to analyze NMR relaxation experiments, for these aqueous electrolytes and highlight the link between the collective dynamics of the liquid underlying the EFG fluctuations at the ion positions and the stress fluctuations. Our results generalize observations for Na+ in aqueous NaCl solutions, showing that models assuming a viscous model of the solvent dynamics are insufficient to describe EFG fluctuations in these systems and illustrate the relevance of molecular simulations to interpret NMR relaxation experiments in terms of microscopic dynamics.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 17","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143967048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vacuum ultraviolet photoionization and dissociative photoionization of acetyl (CH3CO) and vinoxy (CH2CHO) radicals. 乙酰基（CH3CO）和维氧基（CH2CHO）自由基的真空紫外光离和解离光离。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0268925

Cuihong Zhang, Yu Xia, Xiangkun Wu, Christa Fittschen, Jean-Christophe Loison, Gustavo A García, Laurent Nahon, Luis Bañares, Jesús González-Vázquez, Alexandre Zanchet, Xiaofeng Tang

{"title":"Vacuum ultraviolet photoionization and dissociative photoionization of acetyl (CH3CO) and vinoxy (CH2CHO) radicals.","authors":"Cuihong Zhang, Yu Xia, Xiangkun Wu, Christa Fittschen, Jean-Christophe Loison, Gustavo A García, Laurent Nahon, Luis Bañares, Jesús González-Vázquez, Alexandre Zanchet, Xiaofeng Tang","doi":"10.1063/5.0268925","DOIUrl":"https://doi.org/10.1063/5.0268925","url":null,"abstract":"The vacuum ultraviolet photoionization and dissociative photoionization of isomeric radicals, acetyl (CH3CO) and vinoxy (CH2CHO), have been studied using synchrotron radiation double imaging photoelectron photoion coincidence (i2PEPICO) spectroscopy. Mass-selected threshold photoelectron spectra (ms-TPES) corresponding to the parent cations (m/z = 43, CH3CO+ and CH2CHO+) and their fragment ions (m/z = 15, CH3+) are measured and assigned based on theoretical calculations. The first and second bands of the ms-TPES of m/z = 43 are mainly unstructured due to the large molecular configuration changes upon photoionization, and they are attributed to contributions of the singlet ground state of CH3CO+ and CH2CHO+. The ms-TPES of m/z = 15 exhibit a rich structure with two vibrational series superimposed onto a broad envelope. The first vibrational series is attributed to the photoionization of the methyl radical (CH3), generated from secondary reactions in the flow tube reactor, while the second series is attributed to pre-dissociation of the triplet electronic state of CH2CHO+, and the statistical dissociation of ground state CH3CO+ in high vibrational levels contributes to the broad envelope. The dissociation mechanisms for the generation of CH3+ from CH3CO+ and CH2CHO+ are also discussed with the aid of a theoretical energy diagram and a breakdown diagram. In particular, a dissociation mechanism is proposed, in which CH2CHO+ in a triplet electronic state first undergoes an intersystem crossing into the singlet electronic state, followed by a structural rearrangement and dissociation into CH3+ along the singlet minimum energy path of CH3CO+.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 17","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144013040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prediction of reaction kinetics for CL-20 and host-guest crystals under high temperature and pressure using neuroevolution potential. 利用神经进化电位预测高温高压下CL-20和主客体晶体的反应动力学。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0258001

Zhi-Qiang Hu, Yi-Fan Xie, Rui Liu, Jian-Li Shao, Peng-Wan Chen

{"title":"Prediction of reaction kinetics for CL-20 and host-guest crystals under high temperature and pressure using neuroevolution potential.","authors":"Zhi-Qiang Hu, Yi-Fan Xie, Rui Liu, Jian-Li Shao, Peng-Wan Chen","doi":"10.1063/5.0258001","DOIUrl":"https://doi.org/10.1063/5.0258001","url":null,"abstract":"The energetic host-guest approach has been successfully applied to design various novel crystal structures. A neuroevolution potential was proposed to predict the reactive kinetics of CL-20 crystals under high temperature and pressure. In this study, molecular dynamics simulations were conducted to investigate the shock compression and thermal decomposition behaviors. During the shock compression process, temperature monitoring revealed the transition of the crystal from the unreacted Hugoniot state to the reacted Hugoniot state, which occurred after the decomposition of CL-20 molecules. The temperature rise in the reacted state followed the order: N2O > CO2 > H2O2 > NCCH3 > β > α > γ > ε. These indicate that guest molecules facilitate the reaction under shock conditions. During the thermal decomposition process, monitoring the potential energy evolution showed that the initial decomposition of CL-20 molecules is an endothermic reaction, primarily producing NO2. As the temperature increased, NO2 was further consumed, and CL-20 underwent a ring-opening reaction, primarily generating CO2. NCCH3 and H2O2 molecules were consumed during the endothermic process, showing the largest and smallest potential energy changes, respectively. N2O molecules were consumed during the formation of final products, while CO2 and H2O were the final products and were not consumed. The activation energy ranking of the reactions was ε > β > γ > NCCH3 > N2O > CO2 > α > H2O2. These results provide an atomic-level perspective for controlling the detonation performance of energetic materials under high temperature and pressure.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 17","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144026277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observation of the interaction between Au- and CO2 in Au(CO2)n- anions: Physisorption as the dominant mechanism. Au(CO2)n阴离子中Au-与CO2相互作用的观察：物理吸附为主要机制。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0265399

Zonghui Guo, Shihu Du, Wei Huang, Wenbao Zhao, Haiyan Han, Zhi Zhao, Yongliang Yan, Zhihui Fan, Ruili Shi, Hua Xie, Ling Jiang

{"title":"Observation of the interaction between Au- and CO2 in Au(CO2)n- anions: Physisorption as the dominant mechanism.","authors":"Zonghui Guo, Shihu Du, Wei Huang, Wenbao Zhao, Haiyan Han, Zhi Zhao, Yongliang Yan, Zhihui Fan, Ruili Shi, Hua Xie, Ling Jiang","doi":"10.1063/5.0265399","DOIUrl":"https://doi.org/10.1063/5.0265399","url":null,"abstract":"In this study, we investigated the structure and bonding of Au(CO2)n- (n = 2, 3) using photoelectron spectroscopy analysis, quantum chemical calculations, and weak interaction analysis. Quantum chemical calculations revealed that the geometries of the physisorbed structures closely aligned with experimental data, suggesting that these configurations were the most stable under the experimental conditions. Conversely, while chemisorbed structures exhibit stronger interactions and considerable CO2 activation, they show less agreement with the observed spectroscopic data. Using the interaction region indicator method, our weak interaction analysis confirmed that van der Waals forces were the dominant interaction in the physisorbed structures. Our experimental results indicate that these physically adsorbed structures are more stable under the conditions of this study. These findings shed light on the interaction mechanisms of Au(CO2)n- (n = 2, 3) at the molecular level and provide new insights into the potential for transition metals to catalytically activate CO2.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 17","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144026429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Schrödinger cat ground state representing two enantiomers of H3O2. Schrödinger cat基态代表H3O2的两个对映体。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0256270

ChunMei Liu, Jörn Manz, Jian Wen, Yonggang Yang

引用次数: 0

Growth of particles in a ternary melt. 三元熔体中颗粒的生长。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0255527

M L Zhang, M W Chen, N Liu, C M Yang, Z D Wang

引用次数: 0

Response to "Comment on 'A random batch Ewald method for charged particles in the isothermal-isobaric ensemble'" [J. Chem. Phys. 162, 177101 (2025)]. 对“等温-等压系综中带电粒子的随机批处理Ewald方法”的评论[J]。化学。物理学报，2002,17(5):557 - 557。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0255447

Jiuyang Liang, Pan Tan, Liang Hong, Shi Jin, Zhenli Xu, Lei Li

引用次数: 0

Aneesur Rahman: Pioneer of molecular simulation. Aneesur Rahman：分子模拟的先驱。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0273655

Srikanth Sastry

引用次数: 0

Evaluating wavefunction methods, the counterpoise correction, and the frozen core approximation for the optimization of van der Waals dimers. 评估范德华二聚体优化的波函数方法、平衡校正和冻结核近似。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0268710

Caroline S Glick, Rameshwar L Kumawat, C David Sherrill

{"title":"Evaluating wavefunction methods, the counterpoise correction, and the frozen core approximation for the optimization of van der Waals dimers.","authors":"Caroline S Glick, Rameshwar L Kumawat, C David Sherrill","doi":"10.1063/5.0268710","DOIUrl":"https://doi.org/10.1063/5.0268710","url":null,"abstract":"A number of benchmarking studies have assessed the accuracy of various electronic structure methods for computing the interaction energies of van der Waals dimers, but fewer have systematically assessed the quality of dimer geometries obtained by these methods. We present optimized geometries of 21 van der Waals dimers using a highly accurate level of theory, namely coupled-cluster through perturbative triples at the complete basis set limit [CCSD(T)/CBS], and compare these results with optimizations performed at lower levels of theory. The lower levels of theory include variants of Møller-Plesset perturbation theory (MP2, MP2D, and MP2.5) and coupled-cluster theory [CCSD and CCSD(T)], with basis sets ranging from double- to quadruple-zeta. The accuracy of these methods is assessed by comparing errors in the least-root-mean-squared deviations (LRMSDs) of atomic coordinates, center-of-mass distances (ΔdCOM), interaction energies, and rotational constants. We also investigate the impact of the counterpoise correction and the frozen core approximation on the quality of the optimized geometries. Our findings show that increasing the basis set size beyond double-zeta significantly improves the accuracy of the geometries, while further improvements due to the basis set size depend on the method used. The frozen core approximation induces very small changes in geometries, while the counterpoise correction has a larger effect. For double-zeta basis sets, the counterpoise correction tends to degrade the quality of the optimized geometries, regardless of the method used. Several methods yield geometries with LRMSDs and ΔdCOM within 0.1 Å for all 21 dimers, and MP2D with the aug-cc-pVTZ basis set emerges as the most computationally efficient among these well-performing approaches with an average LRMSD and an absolute ΔdCOM of 0.02 Å.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 17","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144025750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0