Journal of Chemical Physics最新文献_第7页

Mixed-valence molecules as platforms for ultrafast cooling via sudden electric-field switching. 混合价分子作为通过突然电场开关进行超快冷却的平台。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0354256

Andrew Palii, Boris Tsukerblat

{"title":"Mixed-valence molecules as platforms for ultrafast cooling via sudden electric-field switching.","authors":"Andrew Palii, Boris Tsukerblat","doi":"10.1063/5.0354256","DOIUrl":"https://doi.org/10.1063/5.0354256","url":null,"abstract":"In this article, we propose the concept of ultrafast cooling under sudden electric field quenching based on the use of binuclear mixed valence (MV) molecules. The formalism earlier developed in the study of molecular quantum cellular automata is used by considering the scenario in which one polarized MV dimer (\"driver-cell\") creates a dipole electric field acting on the adjacent dimer (\"working cell\"). To describe such dimers, the conventional vibronic theory of MV compounds adapted to the present case is applied. The considered process includes two distinct stages: (1) sudden decrease in the driver-cell polarization leading to a violation of the thermal equilibrium, and (2) subsequent dielectric relaxation restoring the thermal equilibrium, accompanied by the heat exchange between the dimers and the phonon bath. In search of a switching regime under which such a two-step process is accompanied by heat absorption (cooling), we face the need to suppress as much as possible the transitions between the ground and excited vibronic states. This is shown to be possible if the fast partial quenching of the driver-cell polarization occurs without changing its sign and also provided that the polarization does not approach too close to the avoided crossing point of two low-lying vibronic levels vs field. For this switching regime, the heat absorption arises from decreasing the energy gap between the two low-lying levels, which creates underpopulation of the excited level, resulting in heat transfer from the phonon bath to the quantum subsystem, i.e., cooling of the environment. It is shown that for systems with a strong vibronic coupling and/or weak electron transfer, this type of cooling is possible for a wider range of the driver-cell polarization variation, which makes MV systems with weak delocalization promising candidates for performing ultrafast cooling.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"165 13","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110409","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

Coherent-state field-theoretic simulations of fluctuation-dominated reaction-diffusion systems. 波动主导反应扩散系统的相干态场论模拟。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0356191

Yao Xiong, Christopher Balzer, Ethan C McGarrigle, Glenn H Fredrickson

{"title":"Coherent-state field-theoretic simulations of fluctuation-dominated reaction-diffusion systems.","authors":"Yao Xiong, Christopher Balzer, Ethan C McGarrigle, Glenn H Fredrickson","doi":"10.1063/5.0356191","DOIUrl":"https://doi.org/10.1063/5.0356191","url":null,"abstract":"Stochastic reaction-diffusion systems can exhibit fluctuation-dominated kinetics that is not captured by well-mixed rate equations, particularly at and below the upper critical dimension. Here, we develop and benchmark a coherent-state field-theoretic simulation framework derived from the Doi-Peliti representation of microscopic reaction-diffusion dynamics. Using single-species annihilating random walks, A + A → ∅, as a test model, we compare two complementary numerical treatments: direct complex Langevin (CL) sampling of the Doi-Peliti coherent-state action in fictitious time and a semi-classical (Semi-C) representation, leading to a stochastic Langevin dynamics in real time. In three dimensions, both approaches recover mean-field (MF) density decay within their respective stability windows, while the Semi-C method remains stable over substantially longer real times. In two dimensions, the Semi-C calculations exhibit finite-time deviations from MF kinetics and reaction-rate-dependent crossover behavior consistent with marginal fluctuation effects. In one dimension, the Semi-C treatment captures the expected early to intermediate crossover toward slower-than-MF decay but develops a late-time plateau when the quadratic annihilation contribution becomes statistically unresolved with the available trajectory ensemble. In both one and two dimensions, the direct CL approach exhibits poor stability and is thus impractical. Semi-C simulations were used to access equal-time connected structure factors and investigate non-uniform initial conditions, revealing fluctuation-induced spatial anticorrelations and finite-time memory of initial geometry. Overall, these results establish that Semi-C outperforms CL in fluctuation-dominated regimes of reaction-diffusion models formulated using the Doi-Peliti coherent-state framework. This work also provides a foundation for extensions to multispecies reactions, reversible association, aggregation, and chemically active soft matter.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"165 13","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110388","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

Intramolecular relaxation of block copolymeric rings in dilute solutions. 嵌段共聚环在稀溶液中的分子内弛豫。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0349889

Sumit Kumar, Parbati Biswas

{"title":"Intramolecular relaxation of block copolymeric rings in dilute solutions.","authors":"Sumit Kumar, Parbati Biswas","doi":"10.1063/5.0349889","DOIUrl":"https://doi.org/10.1063/5.0349889","url":null,"abstract":"The viscoelastic properties of block copolymeric rings are investigated within the framework of optimized Rouse-Zimm theory. A multiresolution bead spring model is used to depict ring block copolymers, which accounts for the variable sizes of the beads connected via different harmonic springs. The hydrodynamic interactions between these beads are approximated using the preaveraged Oseen tensor. The viscoelastic properties of these ring block copolymers are evaluated from the relaxation rates of their respective normal modes. The relaxation dynamics of ring block copolymers are enhanced and retarded in the low and high frequency regimes, respectively, with an increase in the monomeric block length. The storage modulus for ring diblock copolymers reveals a quasi-plateau regime, indicating a solid-like response, whereas the loss modulus exhibits a bimodal pattern due to a difference in the relaxation dynamics of the A- and B-type monomeric domains, unlike the ring homopolymers and multiblock copolymers. The loss tangent displays two quasi-plateaus corresponding to two dynamically distinct monomeric domains. Homopolymeric rings are maximally compact compared to those of ring multiblock and diblock copolymers. The compactness of the ring diblock copolymers decreases with an increase in the size of the B-type monomers. The characteristic overall relaxation time of ring alternating copolymers is lower than that of ring diblock copolymers, indicating a slower dynamics that spans over different time scales. The ring size has no effect on the characteristic overall relaxation time of the ring diblock copolymers unlike that of the ring alternating copolymers.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"165 13","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110397","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

A QM/MM calculation to identify a low frequency mode that causes anharmonic vibrational coupling in green fluorescent protein. 一个QM/MM计算，以确定低频模式，导致绿色荧光蛋白的非谐波振动耦合。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0354017

Tomotsumi Fujisawa, Masashi Unno

引用次数: 0

Thermal conductivity of water from ambient to cryogenic conditions: Thermal history effects in amorphous solid water. 从环境到低温条件下水的导热性：在非晶固体水中的热历史效应。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0348901

Ove Andersson, Changqing Jin

{"title":"Thermal conductivity of water from ambient to cryogenic conditions: Thermal history effects in amorphous solid water.","authors":"Ove Andersson, Changqing Jin","doi":"10.1063/5.0348901","DOIUrl":"https://doi.org/10.1063/5.0348901","url":null,"abstract":"Thermal processes in amorphous solid water (ASW), including those relevant to cryogenic and astrophysical environments, depend sensitively on its thermal conductivity, κ. However, κ is not a unique material constant for amorphous water; rather, it is governed by preparation and thermal history, which determine whether the structure is predominantly low-density or high-density. Amorphous water can be produced by hyperquenching micrometer-sized droplets to form hyperquenched glassy water (HGW), by low-temperature vapor deposition to form ASW, by pressure-induced amorphization of hexagonal ice to form high-density amorphous ice (HDA), and by transformation of HDA to low-density amorphous ice (LDA). Guided by reported structural correspondences linking HGW and ASW formed or annealed at higher temperatures to LDA-like structures and some very-low-temperature ASW deposits to structures with HDA-like characteristics, we analyze κ data across liquid, crystalline, and amorphous forms of water to estimate limiting κ values for nonporous amorphous water. We find κ = (1.5 ± 0.1) W m-1 K-1 for LDA-like amorphous water in the 70-100 K range and κ = (0.2 ± 0.1) W m-1 K-1 for HDA-like amorphous water in the 10-30 K range. These results define limiting intrinsic κ values for nonporous amorphous water and provide reference points for future treatments of porous ASW in vapor-deposited and astrophysical ice environments.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"165 13","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110288","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

Variance reduction for forces and pressure in variational Monte Carlo. 变分蒙特卡罗中力和压力的方差减少。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0336683

David Linteau, Saverio Moroni, Giuseppe Carleo, Markus Holzmann

{"title":"Variance reduction for forces and pressure in variational Monte Carlo.","authors":"David Linteau, Saverio Moroni, Giuseppe Carleo, Markus Holzmann","doi":"10.1063/5.0336683","DOIUrl":"https://doi.org/10.1063/5.0336683","url":null,"abstract":"We present simple and practical strategies to reduce the variance of Monte Carlo estimators. Our focus is on variational Monte Carlo calculations of atomic forces and pressure in electronic systems, although we show that the underlying ideas apply more broadly to other observables, like pair-correlation and angular-distribution functions, and other methods, including molecular dynamics. For Pulay-type contributions, we show that a minor modification based on the Metropolis acceptance ratio softens the power-law divergence of the variance to a logarithmic one, thus reducing the tails of the distribution. Proposal averaging can be added to remove this nodal divergence completely or, alternatively, inexpensive regularizations can be applied to suppress remaining outliers at the price of a controlled small bias. For Hellmann-Feynman forces, we derive compact variance-reduced estimators for periodic systems that are straightforward to implement in standard Monte Carlo codes. The approach is illustrated for high-pressure metallic hydrogen with more than a hundred atoms described by neural quantum states, including an application to molecular dynamics driven by the improved forces.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"165 13","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110234","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

Adsorption energies and decomposition barrier heights for ethylene carbonate on the surface of lithium from cluster-based quantum chemistry. 基于团簇量子化学的碳酸乙烯在锂表面的吸附能和分解势垒高度。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0335668

Ethan A Vo, Hung T Vuong, Zachary K Goldsmith, Hong-Zhou Ye, Yujing Wei, Sohang Kundu, Ardavan Farahvash, Garvit Agarwal, Richard A Friesner, Timothy C Berkelbach

{"title":"Adsorption energies and decomposition barrier heights for ethylene carbonate on the surface of lithium from cluster-based quantum chemistry.","authors":"Ethan A Vo, Hung T Vuong, Zachary K Goldsmith, Hong-Zhou Ye, Yujing Wei, Sohang Kundu, Ardavan Farahvash, Garvit Agarwal, Richard A Friesner, Timothy C Berkelbach","doi":"10.1063/5.0335668","DOIUrl":"https://doi.org/10.1063/5.0335668","url":null,"abstract":"For ethylene carbonate on the (100) surface of lithium, we calculate the adsorption energy in two binding motifs and the barrier height for a ring-opening decomposition reaction. We validate a scheme for producing results in the thermodynamic limit by correcting results obtained on finite lithium clusters containing only 40-100 atoms, which enables the use of hybrid density functionals, random-phase approximation, and correlated wavefunction theories, such as coupled-cluster theory and auxiliary-field quantum Monte Carlo. We find that the high-level theories agree to within 2-5 kcal/mol and can, therefore, serve as benchmarks for more affordable methods. Using our reference data, we demonstrate that generalized gradient approximation functionals, such as PBE, are not sufficiently accurate for reaction barrier heights, and we identify ωB97X-V as an especially promising functional for the interfacial chemistry of electrolyte solvents at lithium metal anodes.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"165 13","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110243","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

Spectroscopic signatures and photoabsorption of HSSCl and H(S)ClS. HSSCl和H(S)ClS的光谱特征和光吸收。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0353701

Tarek Trabelsi, Joseph S Francisco

{"title":"Spectroscopic signatures and photoabsorption of HSSCl and H(S)ClS.","authors":"Tarek Trabelsi, Joseph S Francisco","doi":"10.1063/5.0353701","DOIUrl":"https://doi.org/10.1063/5.0353701","url":null,"abstract":"Chlorine-sulfur coupling is expected to influence Venus's middle-atmosphere photochemistry and may participate, directly or indirectly, in the chemistry linked to the long-standing \"unknown\" near-ultraviolet (UV) absorber. Here, we present a high-level ab initio study of the HClS2 isomers HSSCl and H(S)ClS, providing benchmark structural, rovibrational, and electronic data required for laboratory identification and photochemical modeling. Equilibrium structures and spectroscopic constants are obtained with CCSD(T)-F12/aug-cc-pVTZ and CCSD(T)/aug-cc-pV(Q+d)Z, while anharmonic fundamentals/overtones and vibrationally averaged rotational constants are computed using a rovibrational configuration interaction treatment. The results confirm HSSCl as the global minimum, with H(S)ClS higher by 0.83 eV, consistent with previous thermochemical surveys. HSSCl exhibits negligible near-UV/visible absorption and a far-UV-dominated cross section near 200 nm, implying photochemical stability in the 200-500 nm window, whereas H(S)ClS shows a strong near-UV band centered near 295 nm. Excited-state scans indicate predominantly direct, repulsive dissociation along the Cl-S and S-S stretching coordinates for HSSCl, favoring radical-forming channels such as SH + ClS and HS2 + Cl over ClS2 + H. These data enable quantitative photolysis-rate calculations and provide spectral fingerprints for experimental and observational searches.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"165 13","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110244","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

Fine 3D free energy map of diffusing small molecules in heterogeneous solid media. 非均质固体介质中扩散小分子的精细三维自由能图。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0351844

Kazushi Fujimoto, Zhiye Tang, Tetsuro Nagai, Susumu Okazaki

{"title":"Fine 3D free energy map of diffusing small molecules in heterogeneous solid media.","authors":"Kazushi Fujimoto, Zhiye Tang, Tetsuro Nagai, Susumu Okazaki","doi":"10.1063/5.0351844","DOIUrl":"https://doi.org/10.1063/5.0351844","url":null,"abstract":"An efficient free energy calculation method is proposed for diffusing small molecules in heterogeneous solid media, such as polymers and inorganic solids, to obtain fine three-dimensional (3D) free energy maps consisting of one million meshes. The free energy of transfer of molecules from vacuum to individual meshes in the media was calculated according to the Widom equation using a new importance sampling method. The method simultaneously samples configurations of thousands of test molecules, each independently following a single-particle canonical distribution. The sampling was also accelerated using a high-temperature sampling method. The computational cost of the proposed method is considerably lower than that of the conventional particle insertion method, which relies on inefficient random sampling. Here, we demonstrate the present method by applying it to water molecules in polylactic acid and polypropylene, yielding fine 3D free energy maps with a resolution of 0.05 nm. The free energy integrated over the entire simulation cell showed excellent agreement with values independently obtained using the conventional particle insertion method applied to the entire space. The calculated results also showed good correspondence with experimental water absorption rates. The method is expected to facilitate molecular-level studies of absorption mechanisms, including the spatial distribution of absorption sites, their molecular structures, and the corresponding absorption free energies. The resulting maps also provide abundant information on microscopic diffusion mechanisms, such as 3D diffusion pathway networks formed by spatially distributed free energy saddle points connected by slopes from the absorption sites.","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"165 13","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110352","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

Variational formulation for the dynamics of soft matter including inertia. 含惯性的软物质动力学的变分公式。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0353625

Andrew J Archer

引用次数: 0