Paul S Bagus, Connie J Nelin, Michel Sassi, Daniel Baranowski, Marcus A Sharp, Tom Autrey, Zdenek Dohnálek, Zbynek Novotny
{"title":"The XPS of pyridine: A combined theoretical and experimental analysis.","authors":"Paul S Bagus, Connie J Nelin, Michel Sassi, Daniel Baranowski, Marcus A Sharp, Tom Autrey, Zdenek Dohnálek, Zbynek Novotny","doi":"10.1063/5.0249190","DOIUrl":"https://doi.org/10.1063/5.0249190","url":null,"abstract":"<p><p>A detailed analysis of the N(1s) and C(1s) X-Ray Photoelectron Spectroscopy (XPS) is made, where the measured XPS is compared with theoretical Sudden Approximation (SA) intensities and theoretical XPS Binding Energies (BEs). There is remarkably good agreement between the theoretical predictions and the measured XPS; in particular, the different full width at half maximum values for the C(1s) and N(1s) BEs are explained in terms of unresolved C(1s) BEs for the different C atoms in pyridine. This work demonstrates that the combination of theory and XPS measurements can extract analysis of the XPS relevant to the molecular electronic structure. The theory used is based on fully relativistic self-consistent field solutions of the Dirac-Coulomb Hamiltonian, and the SA is used to determine relative XPS intensities.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501513","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}
Pablo F Zubieta Rico, Gustavo R Pérez-Lemus, Juan J de Pablo
{"title":"Efficient sampling of free energy landscapes with functions in Sobolev spaces.","authors":"Pablo F Zubieta Rico, Gustavo R Pérez-Lemus, Juan J de Pablo","doi":"10.1063/5.0221263","DOIUrl":"https://doi.org/10.1063/5.0221263","url":null,"abstract":"<p><p>Molecular simulations of biological and physical phenomena generally involve sampling complicated, rough energy landscapes characterized by multiple local minima. In this work, we introduce a new family of methods for advanced sampling that draw inspiration from functional representations used in machine learning and approximation theory. As shown here, such representations are particularly well suited for learning free energies using artificial neural networks. As a system evolves through phase space, the proposed methods gradually build a model for the free energy as a function of one or more collective variables, from both the frequency of visits to distinct states and generalized force estimates corresponding to such states. Implementation of the methods is relatively simple and, more importantly, for the representative examples considered in this work, they provide computational efficiency gains of up to several orders of magnitude over other widely used simulation techniques.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501506","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}
Matthew Gerry, Jonathan J Wang, Joanna Li, Ofir Shein-Lumbroso, Oren Tal, Dvira Segal
{"title":"Machine learning delta-T noise for temperature bias estimation.","authors":"Matthew Gerry, Jonathan J Wang, Joanna Li, Ofir Shein-Lumbroso, Oren Tal, Dvira Segal","doi":"10.1063/5.0250879","DOIUrl":"https://doi.org/10.1063/5.0250879","url":null,"abstract":"<p><p>Delta-T shot noise is activated in temperature-biased electronic junctions, down to the atomic scale. It is characterized by a quadratic dependence on the temperature difference and a nonlinear relationship with the transmission coefficients of partially opened conduction channels. In this work, we demonstrate that delta-T noise, measured across an ensemble of atomic-scale junctions, can be utilized to estimate the temperature bias in these systems. Our approach employs a supervised machine learning algorithm to train a neural network, with input features being the scaled electrical conductance, the delta-T noise, and the mean temperature. Due to limited experimental data, we generate synthetic datasets, designed to mimic experiments. The neural network, trained on these synthetic data, was subsequently applied to predict temperature biases from experimental datasets. Using performance metrics, we demonstrate that the mean bias-the deviation of predicted temperature differences from their true value-is less than 1 K for junctions with conductance up to 4G0. Our study highlights that, while a single delta-T noise measurement is insufficient for accurately estimating the applied temperature bias due to noise contributions from other sources, averaging over an ensemble of junctions enables predictions within experimental uncertainties. This suggests that machine learning approaches can be utilized for estimation of temperature biases and similarly other stimuli in electronic junctions.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501508","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}
Stephen H Yuwono, Run R Li, Tianyuan Zhang, Xiaosong Li, A Eugene DePrince
{"title":"Two-component relativistic equation-of-motion coupled cluster for electron ionization.","authors":"Stephen H Yuwono, Run R Li, Tianyuan Zhang, Xiaosong Li, A Eugene DePrince","doi":"10.1063/5.0248535","DOIUrl":"https://doi.org/10.1063/5.0248535","url":null,"abstract":"<p><p>We present an implementation of the relativistic ionization-potential (IP) equation-of-motion coupled-cluster (EOMCC) with up to 3-hole-2-particle (3h2p) excitations that makes use of the molecular mean-field exact two-component framework and the full Dirac-Coulomb-Breit Hamiltonian. The closed-shell nature of the reference state in an X2C-IP-EOMCC calculation allows for accurate predictions of spin-orbit splittings in open-shell molecules without breaking degeneracies, as would occur in an excitation-energy EOMCC calculation carried out directly on an unrestricted open-shell reference. We apply X2C-IP-EOMCC to the ground and first excited states of the HCCX+ (X = Cl, Br, I) cations, where it is demonstrated that a large basis set (i.e., quadruple-zeta quality) and 3h2p correlation effects are necessary for accurate absolute energetics. The maximum error in calculated adiabatic IPs is on the order of 0.1 eV, whereas spin-orbit splittings themselves are accurate to ≈0.01 eV, as compared to experimentally obtained values.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501517","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}
{"title":"Pulsed discharge jet laser spectroscopy of the stibino (SbH2) free radical: Hyperfine and isotopic structure in the high-resolution electronic spectrum.","authors":"Fumie X Sunahori, Dennis J Clouthier","doi":"10.1063/5.0256316","DOIUrl":"https://doi.org/10.1063/5.0256316","url":null,"abstract":"<p><p>The Ã2A1-X̃2B1 0-0 bands of the overlapping LIF spectra of 121SbH2 and 123SbH2 have been recorded at high resolution under supersonic expansion conditions. The radicals were made by a pulsed electric discharge through a dilute mixture of SbH3 in high pressure argon at the exit of a pulsed molecular beam valve. The Sb isotopic lines, magnetic hyperfine structure, and large spin-rotation splittings have been assigned in the spectra. The transitions of the two isotopologues were fitted independently, and the rotational constants were used to obtain the following zero-point effective molecular structures: r″ = 1.7203(1) Å, θ″ = 90.370(4)°; r' = 1.6915(4) Å and θ' = 120.80(2)°. The fitted molecular constants have been validated using isotope relations and by comparison with theoretical formulas. The T0 antimony isotope splitting of SbH2 is only 0.0098 cm-1.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501510","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}
{"title":"State-to-state integral cross sections for the Cl + CHD3 (vCH = 0,1) → HCl + CD3 reactions.","authors":"Shu Liu, Dong H Zhang","doi":"10.1063/5.0256166","DOIUrl":"https://doi.org/10.1063/5.0256166","url":null,"abstract":"<p><p>To precisely study the effect of CH stretch excitation, we calculate the first seven-dimensional state-to-state integral cross sections (ICSs) for the Cl + CHD3(vCH = 0,1) → HCl + CD3 reactions using the time-dependent wave-packet approach on a highly accurate fundamental invariant neural network potential energy surface. Compared to experiments that focus solely on CD3(v2 = 0), our theoretical calculations give a more global picture. It is found that the vibrational enhancement factors of the total ICS are less than 1 only in the very low collision energy region (<0.55 kcal/mol); moreover, the CH stretch-excited reaction also produces vibrationally cold HCl. These two findings indicate that Polanyi's rules apply to this late-barrier polyatomic reaction, not only in terms of the energy requirement in the breaking bond but also in the energy disposal in the newly formed bond. In addition, although the experimental and theoretical product HCl(v1 = 1) branching fractions for CD3(v2 = 0) are in quantitative agreement, the new quantum vibrational enhancement factor for CD3(v2 = 0) is ∼2.7 times greater than the experimental results.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 7","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143448857","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}
Elisabeth Keller, Volker Blum, Karsten Reuter, Johannes T Margraf
{"title":"Exploring atom-pairwise and many-body dispersion corrections for the BEEF-vdW functional.","authors":"Elisabeth Keller, Volker Blum, Karsten Reuter, Johannes T Margraf","doi":"10.1063/5.0248728","DOIUrl":"https://doi.org/10.1063/5.0248728","url":null,"abstract":"<p><p>The Bayesian error estimation functional (BEEF-vdW) is widely used in surface science and catalysis, because it provides a balanced description of molecular, surface, and solid state systems, along with reliable error estimates. However, the nonlocal van-der-Waals density functional (vdW-DF2) employed in BEEF-vdW can be computationally costly and displays relatively low accuracy for molecular systems. Therefore, this work explores whether atom-pairwise and many-body dispersion treatments represent viable alternatives to using the vdW-DF2 functional with BEEF-vdW. To this end, we investigate the performance of commonly used atom-pairwise corrections [i.e., the Tkatchenko-Scheffler (TS) and the exchange-hole dipole moment (XDM) approaches] and many-body dispersion (MBD) treatments for molecular, surface, and solid-state systems. The results indicate that atom-pairwise methods such as TS and particularly XDM provide a good balance of cost and accuracy across all systems.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 7","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143458170","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}
M Elious Mondal, A Nickolas Vamivakas, Steven T Cundiff, Todd D Krauss, Pengfei Huo
{"title":"Polariton spectra under the collective coupling regime. II. 2D non-linear spectra.","authors":"M Elious Mondal, A Nickolas Vamivakas, Steven T Cundiff, Todd D Krauss, Pengfei Huo","doi":"10.1063/5.0249705","DOIUrl":"https://doi.org/10.1063/5.0249705","url":null,"abstract":"<p><p>In our previous work [Mondal et al., J. Chem. Phys. 162, 014114 (2025)], we developed several efficient computational approaches to simulate exciton-polariton dynamics described by the Holstein-Tavis-Cummings (HTC) Hamiltonian under the collective coupling regime. Here, we incorporated these strategies into the previously developed Lindblad-partially linearized density matrix (L-PLDM) approach for simulating 2D electronic spectroscopy (2DES) of exciton-polariton under the collective coupling regime. In particular, we apply the efficient quantum dynamics propagation scheme developed in Paper I to both the forward and the backward propagations in the PLDM and develop an efficient importance sampling scheme and graphics processing unit vectorization scheme that allow us to reduce the computational costs from O(K2)O(T3) to O(K)O(T0) for the 2DES simulation, where K is the number of states and T is the number of time steps of propagation. We further simulated the 2DES for an HTC Hamiltonian under the collective coupling regime and analyzed the signal from both rephasing and non-rephasing contributions of the ground state bleaching, excited state emission, and stimulated emission pathways.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 7","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143458174","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}
Chi-Huan Tung, Lijie Ding, Ming-Ching Chang, Guan-Rong Huang, Lionel Porcar, Yangyang Wang, Jan-Michael Y Carrillo, Bobby G Sumpter, Yuya Shinohara, Changwoo Do, Wei-Ren Chen
{"title":"Scattering-based structural inversion of soft materials via Kolmogorov-Arnold networks.","authors":"Chi-Huan Tung, Lijie Ding, Ming-Ching Chang, Guan-Rong Huang, Lionel Porcar, Yangyang Wang, Jan-Michael Y Carrillo, Bobby G Sumpter, Yuya Shinohara, Changwoo Do, Wei-Ren Chen","doi":"10.1063/5.0253877","DOIUrl":"https://doi.org/10.1063/5.0253877","url":null,"abstract":"<p><p>Small-angle scattering techniques are indispensable tools for probing the structure of soft materials. However, traditional analytical models often face limitations in structural inversion for complex systems, primarily due to the absence of closed-form expressions of scattering functions. To address these challenges, we present a machine learning framework based on the Kolmogorov-Arnold Network (KAN) for directly extracting real-space structural information from scattering spectra in reciprocal space. This model-independent, data-driven approach provides a versatile solution for analyzing intricate configurations in soft matter. By applying the KAN to lyotropic lamellar phases and colloidal suspensions-two representative soft matter systems-we demonstrate its ability to accurately and efficiently resolve structural collectivity and complexity. Our findings highlight the transformative potential of machine learning in enhancing the quantitative analysis of soft materials, paving the way for robust structural inversion across diverse systems.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 7","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143448315","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}
Mauro Ferrario, Giovanni Ciccotti, Daniela Mansutti, Antonio DiCarlo
{"title":"A NEMD approach to the melt-front evolution under gravity.","authors":"Mauro Ferrario, Giovanni Ciccotti, Daniela Mansutti, Antonio DiCarlo","doi":"10.1063/5.0242807","DOIUrl":"https://doi.org/10.1063/5.0242807","url":null,"abstract":"<p><p>Modeling the evolution of the melt front under gravity in the presence of a horizontal thermal gradient is a challenging issue, hitherto tackled exclusively with the concepts and tools of computational continuum thermomechanics, too phenomenologically driven to have satisfactory predictive capabilities. Here, we show that this complex phenomenon is amenable to treatment by the methods and tools of Non-Equilibrium Molecular Dynamics (NEMD). To do so, we addressed all the difficulties caused by the necessity of applying suitable boundary conditions and minimizing surface effects so that the bulk behavior of the system in non-equilibrium conditions can be detected. Sufficient adiabatic separation of the time scales permits us to use macroscopically relatively short-but microscopically long enough-time averages to get the macroscopic bulk behavior of the system accurately. To get an adequate signal-to-noise ratio, we had to use an unphysically large value of the gravity. However, we know from NEMD simulations in transport studies that the phenomena produced are stable over many orders of magnitude. In conclusion, our work proves that molecular simulation can be a good tool to study this family of non-equilibrium phenomena, although further work is needed to achieve quantitative predictive capabilities.</p>","PeriodicalId":15313,"journal":{"name":"Journal of Chemical Physics","volume":"162 7","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143449252","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}