Journal of Chemical Physics最新文献_第10页

Acceleration and twisting of neutral atoms by strong elliptically polarized short-wavelength laser pulses. 强椭圆偏振短波激光脉冲对中性原子的加速和扭转作用。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0263618

Vladimir S Melezhik, Sara Shadmehri

{"title":"Acceleration and twisting of neutral atoms by strong elliptically polarized short-wavelength laser pulses.","authors":"Vladimir S Melezhik, Sara Shadmehri","doi":"10.1063/5.0263618","DOIUrl":"https://doi.org/10.1063/5.0263618","url":null,"abstract":"We have investigated non-dipole effects in the interaction of a hydrogen atom with elliptically polarized laser pulses of intensity (0.25-100) × 1014 W/cm2 with about 8 fs duration. The study was performed within the framework of a hybrid quantum-quasiclassical approach, in which the time-dependent Schrödinger equation for an electron and the classical Hamilton equations for the center-of-mass (CM) of an atom are simultaneously integrated. It is shown that the spatial inhomogeneity k · r of the laser field and the presence of a magnetic component in it lead to the non-separability of the CM and electron variables in a neutral atom and, as a consequence, to its acceleration. We have established a strict correlation between the total probability of excitation and ionization of an atom and the velocity of its CM acquired as a result of interaction with a laser pulse. The acceleration of the atom weakly depends on the polarization of the laser in the considered region (5 eV ≲ ℏω ≲ 27 eV) of its frequencies. However, the transition from linear to elliptical laser polarization leads to the twisting of the atom relative to the axis directed along the propagation of the pulse (coinciding with the direction of the atom acceleration). It is shown that with increasing ellipticity, the twisting effect increases and reaches its maximum value with circular polarization, while the projection of the orbital angular momentum acquired by the electron onto the direction of propagation of the laser pulse reaches its maximum value. A mechanism for n-photon resonant twisting of an atom with the transfer of helicity of photons of a circularly polarized laser field to it has been established, which may be of interest for a number of promising applications.","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":"144009968","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

Ensemble density functional theory with spherically symmetric densities. 球对称密度的系综密度泛函理论。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0255837

Á Nagy

引用次数: 0

Measuring the velocity autocorrelation function using diffusion NMR. 利用扩散核磁共振测量速度自相关函数。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0258081

Teddy X Cai, Nathan H Williamson, Rea Ravin, Magnus Herberthson, Evren Özarslan, Peter J Basser

{"title":"Measuring the velocity autocorrelation function using diffusion NMR.","authors":"Teddy X Cai, Nathan H Williamson, Rea Ravin, Magnus Herberthson, Evren Özarslan, Peter J Basser","doi":"10.1063/5.0258081","DOIUrl":"https://doi.org/10.1063/5.0258081","url":null,"abstract":"Molecular self-diffusion in the presence of barriers results in time-dependent displacements that are controlled by barrier characteristics, such as thickness, arrangement, and permeability, which manifests itself in the form of the ensemble-average velocity autocorrelation function (VAF). We describe a direct method to measure the VAF based on a combination of diffusion-weighted nuclear magnetic resonance (NMR) measurements in which two time-shifted diffusion encodings are separated by a longitudinal storage period. The VAF estimated from simulated data is shown to agree with the known expression for impermeable parallel planes. Simulations of diffusion in periodically spaced, permeable planes and connected, box-shaped pores are also presented. We find that scaling of the VAF faster than t-1/2 is indicative of barrier permeation or exchange between domains and that this can be captured by the proposed method. As an experimental proof-of-concept, we present data from an ex vivo neonatal mouse spinal cord studied using a permanent magnet NMR MOUSE system. We report a transition from t-1/2 to t-3/2 scaling at t ≈ 10 ms, consistent perhaps with transmembrane water exchange. Compared to other NMR-based approaches, this method can potentially access several orders of magnitude in time (ms - s), revealing a wealth of VAF behaviors with one experimental paradigm.","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":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12049238/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143985242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Instabilities of ring-rivulets: Impact of substrate wettability. 环形水流的不稳定性：基材润湿性的影响。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0256308

S Zitz, A Scagliarini, J Roenby

引用次数: 0

Scattering-based structural reconstruction by dimensional elevation. 基于散射的空间高程结构重构。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0257008

Guan-Rong Huang, Chi-Huan Tung, Lionel Porcar, Yuya Shinohara, Changwoo Do, Wei-Ren Chen, Pengwen Chen

{"title":"Scattering-based structural reconstruction by dimensional elevation.","authors":"Guan-Rong Huang, Chi-Huan Tung, Lionel Porcar, Yuya Shinohara, Changwoo Do, Wei-Ren Chen, Pengwen Chen","doi":"10.1063/5.0257008","DOIUrl":"https://doi.org/10.1063/5.0257008","url":null,"abstract":"This study outlines a conceptually new approach for reconstructing the neutron scattering length density profile, Δρ(r), directly from small-angle neutron scattering (SANS) intensity profiles, I(Q). The method is built upon a universal operator A, fundamental to scattering processes, which relates I(Q) to Δρ(r) through the covariance matrix X ≡ Δρ(r)Δρ(r)†. In contrast to conventional SANS data analysis techniques, this approach eliminates the need to predefine a model of Δρ(r) in the regression process. This capability inherently addresses challenges often encountered in existing spectral inversion analysis, such as convergence to local minima due to incomplete analytical models, insufficient orthogonal basis vectors, or non-orthogonality among basis functions in model-free approaches. By extending spectral regression analysis from the vector space of I(Q) to the higher-dimensional space of AXA†, the PhaseLift framework imposes convexity on the regression process. This ensures the stable and computationally efficient reconstruction of the universal minimum Δρ(r) from I(Q). Numerical benchmarks and experimental validations confirm the reliability of this approach in tackling neutron scattering inverse problems. The method establishes a robust and flexible framework for advancing neutron scattering data analysis, with the potential to significantly enhance both the precision and efficiency of experiments across various scientific domains. It provides a solid foundation for further research into the interpretation and application of scattering data.","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":"144009287","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

Response properties from frozen-density embedding approximate second-order coupled-cluster theory. 冻结密度嵌入近似二阶耦合簇理论的响应特性。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0260850

Niklas Niemeyer, Johannes Neugebauer

{"title":"Response properties from frozen-density embedding approximate second-order coupled-cluster theory.","authors":"Niklas Niemeyer, Johannes Neugebauer","doi":"10.1063/5.0260850","DOIUrl":"https://doi.org/10.1063/5.0260850","url":null,"abstract":"We present an implementation of the coupled frozen-density embedding (FDEc) formalism for the calculation of ground-state and excited-state properties, linear-response properties, and transition moments with the coupled cluster with the singles and approximate doubles (CC2) model. Following the general strategy introduced by Höfener and Visscher [J. Chem. Theory Comput.12, 549-557 (2016)], we derive the working equations needed for the evaluation of these properties and describe their implementation into our open-source quantum chemistry program, Serenity. Our implementation comprises both projection-based embedding as well as embedding based on non-additive kinetic-energy functionals and the corresponding potentials. It makes use of the resolution-of-the-identity technique and features-in addition to CC2-the algebraic diagrammatic construction scheme of second order, ADC(2), as well as spin-component-scaled and scaled-opposite spin versions of CC2 and ADC(2). We demonstrate the capabilities of this FDEc framework by analyzing excitation energies, singlet and triplet excitation-energy splittings as well as oscillator strengths of excitonically coupled dimers, the excited-state/difference dipole moment of a formaldehyde⋯water system, and the optical rotatory dispersion of a microsolvated organic chromophore. In the latter case, we reconsider the case of (P)-dimethylallene· (H2O)2, for which uncoupled CC2-based frozen-density embedding fails, while FDEc-time-dependent density-functional theory showed promising results in earlier work. Here, we can confirm that the inclusion of system-environment response couplings leads to agreement with supermolecular CC2 results, highlighting the importance of inter-subsystem couplings in response-property calculations for molecular aggregates.","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":"144011304","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

Femtosecond laser-induced diffusion and desorption of CO adsorbed on a weak electron-phonon coupling surface: Cu(110). 飞秒激光诱导CO在弱电子-声子耦合表面的扩散和解吸：Cu（110）。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0256832

Federico J Gonzalez, Alberto S Muzas, J Iñaki Juaristi, Maite Alducin, H Fabio Busnengo

{"title":"Femtosecond laser-induced diffusion and desorption of CO adsorbed on a weak electron-phonon coupling surface: Cu(110).","authors":"Federico J Gonzalez, Alberto S Muzas, J Iñaki Juaristi, Maite Alducin, H Fabio Busnengo","doi":"10.1063/5.0256832","DOIUrl":"https://doi.org/10.1063/5.0256832","url":null,"abstract":"In this work, we perform molecular dynamics (MD) simulations of CO molecules chemisorbed on Cu(110) under femtosecond laser irradiation. We use the two temperature model and a previously developed potential energy surface based on density functional theory total energies (obtained using the nonlocal vdW-DF2 functional) and parameterized using artificial neural networks. We find that laser irradiation induces diffusion parallel to [1̄10] much more efficiently than parallel to [001] due to a significantly smaller energy barrier in the former case (i.e., 0.12 vs 0.49 eV). We also observe photoinduced desorption (an endothermic process characterized by ΔE = 0.6 eV) with a probability that exhibits a power law dependence with laser fluence. At the lowest fluence studied (F = 30 J m-2), for which experimental data are available, the theoretical photoinduced diffusion probabilities both parallel and perpendicular to [1̄10] agree with the measured values, whereas our calculations predict desorption probabilities smaller than those obtained in experiments. Our MD simulations show that (i) the energy exchange with the hot electron bath is the main responsible for photoinduced processes and (ii) phonons tend to reduce the kinetic energy of the adsorbate, as keeping fixed the position of the Cu atoms during the simulations (thereby quenching CO-phonon energy exchange) significantly increases CO diffusion and desorption probabilities. Thus, our study advances the understanding of ultrafast surface dynamics on metal surfaces with weak electron-phonon coupling, and we hope that it will motivate further experimental investigations.","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":"144026219","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

Single photon emission from point defects in hexagonal boron nitride nanosheets enabled via ambient annealing. 六方氮化硼纳米片中点缺陷的单光子发射。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0269362

Yingying Guo, Yuhan Xiao, Libin Zeng, Jiajin Tai, Wei Zhan, Z Long, Xingwang Zhang, Hong Yin

{"title":"Single photon emission from point defects in hexagonal boron nitride nanosheets enabled via ambient annealing.","authors":"Yingying Guo, Yuhan Xiao, Libin Zeng, Jiajin Tai, Wei Zhan, Z Long, Xingwang Zhang, Hong Yin","doi":"10.1063/5.0269362","DOIUrl":"https://doi.org/10.1063/5.0269362","url":null,"abstract":"Single photon emitters (SPEs) in two-dimensional van der Waals crystals are essential for developing quantum technologies due to their ready integration into photonic circuits and high photon extraction efficiency. Hexagonal boron nitride (h-BN) exhibits an ultra-wide bandgap that can host multiple defect states emitting stable single photons with high brightness at room-temperature. The fabrication and regulation of the defects that determine the spin and optoelectronic physics of h-BN are thus important. Herein, we demonstrate the composite defects modulation in h-BN nanosheets by thermal annealing treatment in air that can generate stable room-temperature SPEs with high photon purity and brightness. Strong and sharp zero-phonon lines appear at ∼386 nm (3.21 eV) and ∼573 nm (2.16 eV) after annealing. The ultraviolet light emission is induced by the formation of a boroxyl ring in h-BN commensurate with the optical transition of nitrogen vacancies, which is characterized by the spectral analysis combined with first-principle calculations. The thermal annealing suppresses the fluorescence background, leading to the population of anti-site nitrogen vacancy complex defects, achieving visible single photon emissions. The results of our work provide a practical post-synthesis process for engineering ensembles of emitters in h-BN for their future integration in quantum photonics.","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":"144016616","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

Molecular simulation of hybrid polymer nanocomposites with organic nanodimers and inorganic nanorods: From structure and dynamics to viscosity. 有机纳米二聚体和无机纳米棒混合聚合物纳米复合材料的分子模拟：从结构、动力学到粘度。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0255157

Adri Escañuela-Copado, Alberto Martín-Molina, Alessandro Patti

{"title":"Molecular simulation of hybrid polymer nanocomposites with organic nanodimers and inorganic nanorods: From structure and dynamics to viscosity.","authors":"Adri Escañuela-Copado, Alberto Martín-Molina, Alessandro Patti","doi":"10.1063/5.0255157","DOIUrl":"https://doi.org/10.1063/5.0255157","url":null,"abstract":"Polymer nanocomposites (PNCs) are cutting-edge materials that enhance polymer matrices with nanoparticles to achieve superior performance. The properties of these composites are significantly influenced by interactions at the nanoparticle-polymer interface. This study explores how inorganic nanorods (NRs) and various organic nanodimers (NDs)-differentiated by their interaction with the polymer and including Janus types-impact the structure, dynamics, and viscosity of PNCs. Through molecular simulations, we reveal how these nanoparticles interact within block copolymer and homopolymer matrices. Our findings show that ND-monomer interactions notably affect ND organization and improve barrier properties, while the structuring of NRs contributes to increased mechanical resistance. Furthermore, different PNCs provide a wide range of thickening behavior depending on the polymer matrix and the embedded nanoparticles. We observe increments of up to six times the melt's viscosity when both nanoparticles are introduced into copolymers. The viscosity of the systems is evaluated using a non-equilibrium method, the SLLOD algorithm, and the Green-Kubo relation to obtain both the shear-thinning curve and the zero-shear viscosity value. These results underscore the importance of nanoparticle interactions and configurations in determining PNC behavior, providing critical insights for advancing material design and functionality.","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":"144003414","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

Femtosecond-and-atom-resolved solvation dynamics of a Na+ ion in a helium nanodroplet. Na+离子在氦纳米液滴中的飞秒-原子溶解动力学。

IF 3.1 2区化学

Journal of Chemical Physics Pub Date : 2025-05-07 DOI: 10.1063/5.0260588

Simon H Albrechtsen, Jeppe K Christensen, Christian E Petersen, Constant A Schouder, Pedro Javier Carchi-Villalta, Iker Sánchez-Pérez, Massimiliano Bartolomei, Tomás González-Lezana, Fernando Pirani, Henrik Stapelfeldt

{"title":"Femtosecond-and-atom-resolved solvation dynamics of a Na+ ion in a helium nanodroplet.","authors":"Simon H Albrechtsen, Jeppe K Christensen, Christian E Petersen, Constant A Schouder, Pedro Javier Carchi-Villalta, Iker Sánchez-Pérez, Massimiliano Bartolomei, Tomás González-Lezana, Fernando Pirani, Henrik Stapelfeldt","doi":"10.1063/5.0260588","DOIUrl":"https://doi.org/10.1063/5.0260588","url":null,"abstract":"Recently, it was shown how the primary steps of solvation of a single Na+ ion, instantly created at the surface of a nanometer-sized droplet of liquid helium, can be followed at the atomic level [Albrechtsen et al., Nature 623, 319 (2023)]. This involved measuring, with femtosecond time resolution, the gradual attachment of individual He atoms to the Na+ ion as well as the energy dissipated from the local region of the ion. In this current work, we provide a more comprehensive and detailed description of the experimental findings of the solvation dynamics and present an improved Poisson-statistical analysis of the time-resolved yields of the Na+Hen ions recorded. For droplets containing an average of 5200 He atoms, this analysis gives a binding rate of 1.84 ± 0.09 atoms/ps for the binding of the first five He atoms to the Na+ ion. In addition, thanks to accurate theoretical values for the evaporation energies of the Na+Hen ions, obtained by path integral Monte Carlo methods using a new potential energy surface presented here for the first time, we improve the determination of the time-dependent removal of the solvation energy from the region around the sodium ion. We find that it follows Newton's law of cooling for the first 5 ps. Measurements were carried out for three different average droplet sizes, ⟨ND⟩ = 9000, 5200, and 3600 helium atoms, and differences between these results are discussed.","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":"144016939","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