Journal of Chemical Physics最新文献_第8页

Chiral conformational fluctuations soften the twist elasticity of nematics. 手性构象波动软化了向列矩阵的扭转弹性。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0349417

Paul van der Schoot

引用次数: 0

Electron density structural torsion. 电子密度结构扭转。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0347585

Minhhuy Hô, Chérif F Matta

{"title":"Electron density structural torsion.","authors":"Minhhuy Hô, Chérif F Matta","doi":"10.1063/5.0347585","DOIUrl":"https://doi.org/10.1063/5.0347585","url":null,"abstract":"Quantum chemical topology (QCT) extracts chemical information from the electron density, ρr, and its derivatives. In this context, however, a direct Helmholtz decomposition of the gradient field of the density, ∇ρr, is uninformative because a gradient field is purely longitudinal. We introduce the density structural torsional vector (DSTV), Fρr=∇lnρrρ0×∇∇2ρr, where ρ0 is a constant positive reference density introduced to make the logarithm dimensionless; its value does not affect the resulting field. The DSTV measures the local directional noncollinearity between the relative density gradient and the spatial variation of the Laplacian of the density and is divergence-free by construction. Its associated scalar descriptors, Sr=sinθr and Sρr=ρrsinθr, where θ(r) is the local angle between the relative density gradient and the gradient of the Laplacian of the density quantify, respectively, the purely angular and density-weighted forms of this noncollinearity, with the latter emphasizing regions of appreciable electron density. Illustrative molecular calculations show that these descriptors reveal anisotropic density-curvature organization, shell structure, and bond-region features that are not immediately evident from the electron density, its gradient, or its Laplacian considered separately. Numerical examples are presented for simple diatomics, including Li2 with a non-nuclear attractor, and the water molecule. The method is proposed as a complementary electron density-derived vectorial descriptor for the real-space analysis of electronic structure.","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":"149110379","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

Reordering-mediated nucleation dynamics in early stage phase separation. 早期相分离中重序介导的成核动力学。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0352183

Kaicheng Zhu, Haibin Su

{"title":"Reordering-mediated nucleation dynamics in early stage phase separation.","authors":"Kaicheng Zhu, Haibin Su","doi":"10.1063/5.0352183","DOIUrl":"https://doi.org/10.1063/5.0352183","url":null,"abstract":"Classical nucleation theories relying on quasi-equilibrium thermodynamics fail to capture the far-from-equilibrium structural reordering inherent to early stage condensed-cluster formation. We develop a framework that maps a continuous structural field onto a core-shell model, coupling local non-conservative reordering with mesoscopic phase-boundary propagation. By evaluating the reordering-mediated nucleation time, we analytically distinguish the static potential energy profile from the effective nucleation barrier. Our mean-field solution reveals a kinetic turnover effect: beyond a critical structural-density coupling threshold, rapid reordering dynamics induce a steep interfacial gradient in the structural field, incurring an energetic penalty that suppresses the net driving force for nucleation. This behavior highlights a fundamental non-reciprocity between cluster growth and local structural relaxation. The reordered intermediate states replicate experimentally observed size-dependent structural gradients and offer a resolution to discrepancies between classical predictions and measured nucleation rates, providing testable criteria for multi-step pathways in nanocrystallization and biomolecular condensation.","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":"149109999","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

Stretch-suppressed segmental dynamics in polymers with different entanglement densities near Tg. Tg附近不同纠缠密度聚合物的拉伸抑制节段动力学。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0353507

Hao Sun, Renkuan Cao, Yunhan Zhang, Tingyu Xu, Liangbin Li

{"title":"Stretch-suppressed segmental dynamics in polymers with different entanglement densities near Tg.","authors":"Hao Sun, Renkuan Cao, Yunhan Zhang, Tingyu Xu, Liangbin Li","doi":"10.1063/5.0353507","DOIUrl":"https://doi.org/10.1063/5.0353507","url":null,"abstract":"Pre-stretching raises the glass transition temperature (Tg) of polymers, yet the underlying microscopic mechanisms remain unclear. This work employs molecular dynamics simulations of polymer systems with different entanglement densities (Ne) to unravel this mechanism. The simulations reproduce the experimentally observed increases in Tg, structural relaxation time (τα), and density after stretching. During stretching, stress-activated flow accelerates segmental dynamics, lowers the density, and raises the enthalpy. Upon subsequent free relaxation, these quantities not only recover but also over-recover their unstretched values, indicating that stretching drives the system into a denser, dynamically slower state. The over-recovery strengthens with increasing Ne and is more pronounced under biaxial stretching. Two quantitative correlations pinpoint the underlying mechanism. First, the evolutions of free volume and τα collapse onto a single linear relation, consistent with the Doolittle equation of free-volume theory. Second, the density scales linearly with the local orientational order parameter. These correlations reveal that stretching induces local orientational ordering, which packs segments more densely, reduces the free volume, and thereby suppresses segmental dynamics. Consistently, upon heating, the internal-energy and density differences between stretched and unstretched systems reach their extrema at the temperature where the local orientation begins to decay, corroborating the coupling between local ordering and dense packing. Entanglements sustain the stretch-induced oriented state, so the effect is amplified at high Ne. These findings clarify how stretching raises Tg and highlight the role of entanglements in stabilizing the stretch-induced glassy state.","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":"149110254","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

Kinetically constrained ring-polymer molecular dynamics extended to all regimes of electronic coupling. 动力学约束环-聚合物分子动力学扩展到所有的电子耦合机制。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0346874

Victor A Suarez, Joshua S Kretchmer

{"title":"Kinetically constrained ring-polymer molecular dynamics extended to all regimes of electronic coupling.","authors":"Victor A Suarez, Joshua S Kretchmer","doi":"10.1063/5.0346874","DOIUrl":"https://doi.org/10.1063/5.0346874","url":null,"abstract":"Kinetically constrained ring-polymer molecular dynamics (KC-RPMD) is an approximate quantum dynamical method for treating electronically non-adiabatic processes in condensed-phase systems, predicting accurate electron transfer (ET) rate constants in the normal and inverted Marcus regimes through computationally efficient classical equations of motion. The favorable properties of KC-RPMD in the weak diabatic coupling regime have been well investigated. However, an in-depth study of its performance in the strong coupling regime has not been performed until now. In this work, we identify a breakdown of free energies and ET rates predicted by traditional KC-RPMD in the strong coupling regime. We extend KC-RPMD to allow for the direct simulation of systems spanning the full range of diabatic coupling strengths, maintaining all the favorable properties in the weak coupling regime while recovering the appropriate adiabatic description in the strong coupling regime. This is accomplished through a modification to the Gaussian restraint penalty function, which is made to gradually loosen and vanish at strong coupling. We demonstrate the accuracy of KC-RPMD on a variety of spin-boson model systems spanning a wide range of diabatic coupling strengths.","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":"149110315","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

Momentum-resolved non-resonant inelastic x-ray scattering study of C60. C60的动量分辨非共振非弹性x射线散射研究。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0353785

Rui-Qi Tang, Jin-Feng Chen, Tao Xiong, Qing-Wen Gu, Yu-Jun Zhang, Zhi-Ying Guo, Shuo-Xue Jin, Wei Xu, Lin-Fan Zhu

{"title":"Momentum-resolved non-resonant inelastic x-ray scattering study of C60.","authors":"Rui-Qi Tang, Jin-Feng Chen, Tao Xiong, Qing-Wen Gu, Yu-Jun Zhang, Zhi-Ying Guo, Shuo-Xue Jin, Wei Xu, Lin-Fan Zhu","doi":"10.1063/5.0353785","DOIUrl":"https://doi.org/10.1063/5.0353785","url":null,"abstract":"For large molecular systems such as C60, accurate ab initio calculations remain challenging, making experimental methods a more reliable alternative. In this work, we employed the non-resonant inelastic x-ray scattering technique to study the electronic excitation dynamics of C60. The measurements spanned a momentum transfer range of 0.63-5.10 a.u. at a photon energy of ∼10 keV with an energy resolution around 1.0 eV. The dynamic structure factors in the excitation energy range of 5-500 eV and the generalized oscillator strengths for the core excitations of π*←1s were determined on absolute scales. A new feature at ∼24 eV was identified. In addition, the optical oscillator strengths were obtained by extrapolating the generalized oscillator strengths to zero momentum transfer, which show good agreement with the earlier x-ray absorption results. These findings demonstrate that the non-resonant inelastic x-ray scattering is a powerful technique for probing the electronic excitation process and extracting the corresponding dynamic parameters in complex molecular systems.","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":"149110322","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

Polymer-peptide interfacial interactions investigated by molecular dynamics simulations. 高分子-肽界面相互作用的分子动力学模拟研究。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0350724

In-Chul Yeh, Mark T Kozlowski, Joshua A Orlicki

{"title":"Polymer-peptide interfacial interactions investigated by molecular dynamics simulations.","authors":"In-Chul Yeh, Mark T Kozlowski, Joshua A Orlicki","doi":"10.1063/5.0350724","DOIUrl":"https://doi.org/10.1063/5.0350724","url":null,"abstract":"We investigated the interfacial interactions between polymers and peptides using molecular dynamics (MD) simulations. Poly(methyl methacrylate) (PMMA) and polystyrene (PS) were used as representative polymer materials, and phenylalanine dipeptide (FF), serine dipeptide (SS), and two 15-residue sequences served as model peptides. Well-equilibrated configurations were prepared via high-temperature simulations, followed by cooling. First, bulk-phase MD simulations were conducted to evaluate temperature-dependent volumetric properties. The estimated glass transition temperatures (Tg) of PMMA and PS were significantly higher than 300 K, indicating that they are in a glassy state at room temperature, while peptide aggregate Tg values were close to 300 K. Next, simulations of polymer and peptide slabs with vacuum interfaces were performed to calculate surface energies by analyzing potential energy differences between the bulk and slab configurations. The calculated surface energies of PMMA and PS were consistent with experimental surface free energy values reported in the literature, considering entropic contributions and sampling limitations. Finally, we performed MD simulations of polymer/peptide interfaces to examine cross-interface density profiles, phenyl ring orientations, and specific atomic interactions. Interfacial energies were quantified by comparing potential energies of systems with and without interfaces. Notably, polymer/peptide pairs with similar functional groups (e.g., the hydrophobic PS/FF interface) exhibited lower interfacial energies than chemically dissimilar pairs (e.g., PS/SS). A high separation energy was observed at the PMMA/SS interface, indicating favorable interactions between polar functional groups. Our computational approach introduces an alternative protocol for probing interfacial interactions of peptides and can be applied to aid the design of materials with specific interfacial properties.","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":"149110361","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

Coupling residual entropy scaling and revised Enskog theory (REST): A predictive framework for multicomponent transport properties from dilute gas to dense liquid. 耦合剩余熵标度和修正Enskog理论（REST）：稀气到浓液多组分输运特性的预测框架。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0347005

Vegard G Jervell, Øivind Wilhelmsen

{"title":"Coupling residual entropy scaling and revised Enskog theory (REST): A predictive framework for multicomponent transport properties from dilute gas to dense liquid.","authors":"Vegard G Jervell, Øivind Wilhelmsen","doi":"10.1063/5.0347005","DOIUrl":"https://doi.org/10.1063/5.0347005","url":null,"abstract":"Estimating transport properties such as viscosity and thermal conductivity is crucial for a wide range of applications. No theory has yet been presented that is capable of predicting these properties accurately across the entire fluid region. With transfer lengths determined from intermolecular potentials, Revised Enskog Theory (RET) has been shown to yield accurate predictions from dilute gas to the liquid-solid transition at high temperatures. We present a methodology coupling RET with residual entropy scaling (RES), called REST, where the residual entropy scaling is derived from the high-temperature limit of RET. With equilibrium properties from thermodynamic perturbation theory, REST is fully predictive for transport properties of multicomponent mixtures under conditions ranging from dilute gas to dense liquid. It has an average absolute relative deviation (AARD) of 5.30%, 7.07%, and 2.97% for the viscosity of argon, neon, and air, respectively, across the full fluid range. The AARD is 1.3%-4.3% for the viscosity of several binary mixtures containing CH4, CO2, H2, and N2 at temperatures down to 100 K and pressures up to 792 bars. For the CH4/H2 mixture, REST significantly outperforms the present industry standard, which combines empirical correlations for the pure components with extended corresponding states theory. For a range of binary mixtures containing CO2, CH4, O2, and N2, the thermal conductivity is predicted with AARDs of 2.9%-6.3% at pressures up to 200 bars and temperatures ranging from 104 to 425 K, which is within the experimental accuracy. REST combined with the SAFT-VR Sum equation of state predicts the transport properties of argon and neon throughout the entire fluid region using an interaction potential derived from ab initio calculations as the sole input.","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":"149110370","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

Probing symmetry-driven DEA dynamics in ozone investigated by velocity slice imaging technique. 用速度切片成像技术研究臭氧中探测对称驱动的DEA动力学。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0350118

Melvin Varghese, Dharun J, Nigel J Mason, E Krishnakumar, Vaibhav S Prabhudesai, Krishnendu Gope

{"title":"Probing symmetry-driven DEA dynamics in ozone investigated by velocity slice imaging technique.","authors":"Melvin Varghese, Dharun J, Nigel J Mason, E Krishnakumar, Vaibhav S Prabhudesai, Krishnendu Gope","doi":"10.1063/5.0350118","DOIUrl":"https://doi.org/10.1063/5.0350118","url":null,"abstract":"We report the results of a comprehensive experimental investigation of dissociative electron attachment (DEA) to ozone using the velocity slice imaging technique. We reveal several channels that yield both O- and O2- from negative-ion resonances formed by electron attachment. Our results demonstrate that DEA to ozone proceeds through competition between symmetric and asymmetric dissociation pathways. This is governed by excitation of symmetric, asymmetric, and bending vibrational modes and likely involves vibronic coupling between the symmetry of the negative ion resonance states. At 1.6 eV, symmetric dissociation results in vibrationally excited O2 and O2- with near-thermal kinetic energies. An additional asymmetric dissociation pathway driven by overlapping contributions from A21 and B22 states producing rotationally excited O2 with enhanced translational energy is identified. DEA from the second resonance yields both O- and O2- with considerable internal energies arising from a single anionic state (B22) proceeding via an asymmetric dissociation mechanism. In the 4.1-4.4 eV region, overlapping resonances with A1 and B2 symmetry lead to asymmetric dissociation, accompanied by a notable increase in internal excitations of the molecular moieties. This also provides experimental evidence for the previously proposed A12 shape resonance at 4.2 eV. At higher energies around 6.9 eV, angular distribution analysis reveals a contribution from an additional A12 state, in contrast to the theoretically predicted B22 state. These findings establish a unified picture of competing symmetric and asymmetric dissociation mechanisms that produce highly internally excited and chemically reactive fragments.","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":"149109954","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

Accurate starting points for one-shot G0W0 and Bethe-Salpeter equation calculations via effective tuning of range-separated hybrid functionals. 通过对距离分离混合泛函的有效调整，实现了G0W0和Bethe-Salpeter方程计算的精确起点。

IF 3.7 2区化学

Journal of Chemical Physics Pub Date : 2026-10-07 DOI: 10.1063/5.0344368

Aditi Singh, Subrata Jana, Szymon Śmiga

{"title":"Accurate starting points for one-shot G0W0 and Bethe-Salpeter equation calculations via effective tuning of range-separated hybrid functionals.","authors":"Aditi Singh, Subrata Jana, Szymon Śmiga","doi":"10.1063/5.0344368","DOIUrl":"https://doi.org/10.1063/5.0344368","url":null,"abstract":"The accuracy of one-shot G0W0 and Bethe-Salpeter equation (BSE) calculations depends strongly on the underlying starting-point eigensystem, which is commonly obtained from a mean-field density-functional approximation. Range-separated hybrid (RSH) functionals provide a particularly effective starting point; however, conventional optimally tuned RSH procedures often require costly, system-specific, multi-step optimizations of the range-separation parameter ω. In this work, we show that a recently proposed effective tuning protocol [Singh et al., J. Phys. Chem. Lett. 16(32), 8198-8208 (2025)] for RSH functionals can serve as an efficient alternative for determining ω used in G0W0 and BSE calculations. This simplified tuning scheme yields range-separation parameters that are effectively equivalent to those obtained from more elaborate tuning strategies, while avoiding their substantial computational overhead. The resulting tuned RSH eigensystems provide reliable starting points for many-body perturbation theory. In particular, one-shot G0W0 calculations based on effectively tuned RSH orbitals reproduce reference ionization potentials with high accuracy, while subsequent BSE calculations yield quantitatively reliable neutral excitation energies, optical absorption spectra, and excitonic properties for a diverse set of molecular systems and clusters. These results demonstrate that effective RSH tuning offers a practical and broadly applicable route to accurate quasiparticle and excited-state calculations, combining the accuracy of optimally tuned starting points with the low computational cost required for routine applications of G0W0 and BSE.","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":"149110271","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