The Journal of Physical Chemistry A最新文献_第2页

Similarity-Informed Matrix Completion Method for Predicting Activity Coefficients.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 Epub Date: 2025-03-19 DOI: 10.1021/acs.jpca.4c08360

Nicolas Hayer, Thomas Specht, Justus Arweiler, Hans Hasse, Fabian Jirasek

{"title":"Similarity-Informed Matrix Completion Method for Predicting Activity Coefficients.","authors":"Nicolas Hayer, Thomas Specht, Justus Arweiler, Hans Hasse, Fabian Jirasek","doi":"10.1021/acs.jpca.4c08360","DOIUrl":"10.1021/acs.jpca.4c08360","url":null,"abstract":"Accurate prediction of thermodynamic properties of mixtures, such as activity coefficients, is essential for designing and optimizing chemical processes. While established physics-based methods face limitations in prediction accuracy and scope, emerging machine learning approaches, such as matrix completion methods (MCMs), offer promising alternatives. However, their performance can suffer in data-sparse regions. To address this issue, we propose a novel hybrid MCM for predicting activity coefficients at infinite dilution at 298 K that not only uses experimental training data but also includes synthetic training data from two sources: predictions obtained from the physics-based modified UNIFAC (Dortmund) and from a similarity-based approach developed in previous work. The resulting hybrid method combines the broad applicability of MCMs with the precision of the similarity-based approach, resulting in a more robust prediction framework that excels even in regions with limited data. Additionally, our analysis provides valuable insights into how different types of training data affect the prediction accuracy. When experimental data are sparse, incorporating synthetic training data from modified UNIFAC (Dortmund) and the similarity-based approach significantly improves the performance of the MCMs. Conversely, even with abundant experimental data, high accuracy is achieved only if the training set includes mixtures similar to those of interest.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"3141-3147"},"PeriodicalIF":2.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655529","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

Local-Density Correlation Functional from the Force-Balance Equation.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 Epub Date: 2025-03-19 DOI: 10.1021/acs.jpca.4c07235

Nicolas Tancogne-Dejean, Markus Penz, Michael Ruggenthaler, Angel Rubio

引用次数: 0

A Tribute to Alec M. Wodtke.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 DOI: 10.1021/acs.jpca.5c01322

Hua Guo, Gerard Meijer, Xueming Yang

引用次数: 0

Transferability Across Different Molecular Systems and Levels of Theory with the Data-Driven Coupled-Cluster Scheme.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 Epub Date: 2025-03-25 DOI: 10.1021/acs.jpca.4c05718

P D Varuna S Pathirage, Brody Quebedeaux, Shahzad Akram, Konstantinos D Vogiatzis

{"title":"Transferability Across Different Molecular Systems and Levels of Theory with the Data-Driven Coupled-Cluster Scheme.","authors":"P D Varuna S Pathirage, Brody Quebedeaux, Shahzad Akram, Konstantinos D Vogiatzis","doi":"10.1021/acs.jpca.4c05718","DOIUrl":"10.1021/acs.jpca.4c05718","url":null,"abstract":"Machine learning has recently been introduced into the arsenal of tools that are available to computational chemists. In the past few years, we have seen an increase in the applicability of these tools on a plethora of applications, including the automated exploration of a large fraction of the chemical space, the reduction of repetitive computational tasks, the detection of outliers on large databases, and the acceleration of molecular simulations. An attractive application of machine learning in molecular electronic structure theory is the \"recycling\" of molecular wave functions for faster and more accurate completion of complex quantum chemical calculations. Along these lines, we have developed hybrid quantum chemical/machine learning workflows that utilize information from low-level wave functions for the accurate prediction of higher-level wave functions. The data-driven coupled-cluster (DDCC) family of methods is discussed in this article together with the importance of the inclusion of physical properties in such hybrid workflows. After a short introduction to the philosophy and the capabilities of DDCC, we present our recent progress in extending its applicability to larger and more complex molecular structures and data sets. A significant advantage offered by DDCC is its transferability, with respect to different molecular systems and different excitation levels. As we show here, predicted wave functions at the coupled-cluster singles and doubles level of theory can be used for the accurate prediction of the perturbative triples of the CCSD(T) scheme. We conclude with some personal considerations with respect to future directions related to the development of the next generation of such hybrid quantum chemical/machine learning models.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"2988-2997"},"PeriodicalIF":2.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707786","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

UV Photodissociation Dynamics of Organic Hydroperoxides: Experiment and Theory.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 Epub Date: 2025-03-20 DOI: 10.1021/acs.jpca.5c00762

Meijun Zou, Emmanuel Moya Cruz, Christopher A Sojdak, Marisa C Kozlowski, Tolga N V Karsili, Marsha I Lester

{"title":"UV Photodissociation Dynamics of Organic Hydroperoxides: Experiment and Theory.","authors":"Meijun Zou, Emmanuel Moya Cruz, Christopher A Sojdak, Marisa C Kozlowski, Tolga N V Karsili, Marsha I Lester","doi":"10.1021/acs.jpca.5c00762","DOIUrl":"10.1021/acs.jpca.5c00762","url":null,"abstract":"The UV photodissociation dynamics of three organic hydroperoxides (ROOH, R = tert-butyl, cyclopentyl, and cyclohexyl) are examined experimentally at 282 nm utilizing velocity map imaging of the OH X2Π3/2 (v″ = 0, J″) products. The three systems have similar O-O bond dissociation energies based on W1BD calculations and thus similar energy release to products. In each case, the experimental total kinetic energy release (TKER) distributions are bimodal, composed of narrow low and broad high TKER components extending over the available energy. The associated angular distributions of the OH X2Π products are isotropic, differing dramatically from those predicted for direct photodissociation. Complementary theoretical calculations map the relaxed potential energy profile for each ROOH along the steeply repulsive excited state (S1) potential leading to RO + OH products. Low CCOO torsional barriers predicted along the ROOH dissociation pathway enable the OH products to recoil in many different directions, yielding isotropic angular distributions. Simple models of photodissociation suggest that the low TKER component arises from internal conversion to the ground state (S0) potential, leading to a common RO + OH product asymptote. A simple impulsive model for dissociation captures some aspects of the high TKER component but neglects significant geometric changes in the alkyl substituent from ROOH to the RO product. This study provides new insight into the solar photolysis of organic hydroperoxides and the regeneration of OH radicals in atmospheric oxidation cycles.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"3052-3062"},"PeriodicalIF":2.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143668492","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

In Silico Formation of Polyphosphazene Networks Based on Phloroglucinol (Phg) and Hexachlorocyclotriphosphazene (HCCP): Structural and Mechanical Properties as a Function of the Phg:HCCP Ratio.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 Epub Date: 2025-03-25 DOI: 10.1021/acs.jpca.5c00277

Sylvie Neyertz, Méryll Barraco, Nieck E Benes, David Brown

{"title":"In Silico Formation of Polyphosphazene Networks Based on Phloroglucinol (Phg) and Hexachlorocyclotriphosphazene (HCCP): Structural and Mechanical Properties as a Function of the Phg:HCCP Ratio.","authors":"Sylvie Neyertz, Méryll Barraco, Nieck E Benes, David Brown","doi":"10.1021/acs.jpca.5c00277","DOIUrl":"10.1021/acs.jpca.5c00277","url":null,"abstract":"Twenty-four molecular models for polyphosphazene networks were created via an in silico polymerization of phloroglucinol Phg (C6H6O3) and hexachlorocyclotriphosphazene HCCP (N3P3Cl6) mixtures at different Phg:HCCP ratios. A series of monomer mixtures at Phg-to-HCCP stoichiometric ratios ranging from 1:1 to 8:1 were created using molecular dynamics (MD) simulations. Alternating phases of reactions followed by relaxation steps led to the progressive formation of percolating polyphosphazene networks. The actual ratios of Phg to HCCP rings incorporated in the network polymers remained close to those in the mixtures for initial ratios up to 2:1. Above 2:1, there was a gradual divergence toward lower values in the networks as the limits to the number of possible bonds for each monomer started to take effect. The details of the structures were found to be very complex in terms of the probability distributions of links per Phg or HCCP ring. The highest degrees of connectivity and ring packing densities were found in the networks formed from the initial mixtures having Phg-to-HCCP ratios of around 2:1. Mechanical tests were carried out in order to ascertain the resistance of the model polyphosphazene networks to compression/decompression. There again, the networks obtained from the 2:1 initial mixture were found to have the highest Young's modulus and to display the most elasticity as they recovered their initial shape once the compression was removed. The influence of trapped excess monomers in the percolating networks was only noticeable at the highest mixture ratios. The most resistant Phg-HCCP networks are thus obtained from Phg-to-HCCP mixture ratios of around 2:1, with or without trapped excess monomers.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"3148-3165"},"PeriodicalIF":2.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143699110","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

VUV Photoionization Induced Proton Transfer and Formation of New Covalent Bonds in Pyridine-Methanol Complex.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 Epub Date: 2025-03-20 DOI: 10.1021/acs.jpca.5c00286

Bingbing Wu, Yujian Li, Shenghui Xu, Jingyu Li, Ming Wei, Dandan Wang, Min Xie, Yongjun Hu

{"title":"VUV Photoionization Induced Proton Transfer and Formation of New Covalent Bonds in Pyridine-Methanol Complex.","authors":"Bingbing Wu, Yujian Li, Shenghui Xu, Jingyu Li, Ming Wei, Dandan Wang, Min Xie, Yongjun Hu","doi":"10.1021/acs.jpca.5c00286","DOIUrl":"10.1021/acs.jpca.5c00286","url":null,"abstract":"Ion-molecule reactions are a crucial form of reaction in space that can reveal the formation mechanisms and evolutionary processes of some complex interstellar molecules and even prebiotic molecules. In this study, infrared spectra of pyridine (Pyd) and methanol (CH3OH) or deuterated methanol (CH3OD) clusters were measured in the spectral range of 2400-3800 cm-1 using an infrared-vacuum ultraviolet (IR-VUV) scheme. The geometric conformer, infrared spectra of the possible products, and reaction paths were investigated utilizing quantum chemical calculations. By comparing the experimental and theoretically calculated spectra, we found that only a unique hydrogen-bonded structure exists within the Pyd-CH3OH complex, characterized by a linear hydrogen bond conformer between the two constituent molecules. On the other hand, interestingly, we observed a relatively weak NH vibrational peak at 3383 cm-1 in the infrared spectra of both cationic Pyd-CH3OH and Pyd-CH3OD, suggesting that proton transfer has occurred via at least two distinct pathways. These pathways likely involve a proton transfer reaction from either the OH group or the CH3 group of CH3OH to the nitrogen atom of Pyd, with the transfer from the OH group being the predominant route. Through the theoretical calculations, we also found that a new C-C bond can be formed between the two moieties after the proton transfer reactions.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"3012-3019"},"PeriodicalIF":2.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143668494","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

Looking Backward and Forward

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 DOI: 10.1021/acs.jpca.5c0132410.1021/acs.jpca.5c01324

Alec Wodtke*,

引用次数: 0

Isotope Effect on the Few-Femtosecond Relaxation Dynamics of the Ethylene Cation.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 Epub Date: 2025-03-26 DOI: 10.1021/acs.jpca.5c01020

Matteo Lucchini, Manuel Cardosa-Gutierrez, Mario Murari, Fabio Frassetto, Luca Poletto, Mauro Nisoli, Francoise Remacle

{"title":"Isotope Effect on the Few-Femtosecond Relaxation Dynamics of the Ethylene Cation.","authors":"Matteo Lucchini, Manuel Cardosa-Gutierrez, Mario Murari, Fabio Frassetto, Luca Poletto, Mauro Nisoli, Francoise Remacle","doi":"10.1021/acs.jpca.5c01020","DOIUrl":"10.1021/acs.jpca.5c01020","url":null,"abstract":"Few-femtosecond extreme-ultraviolet (EUV) pulses with tunable energy are employed to initiate the Jahn-Teller structural rearrangement in the ethylene cation. We report on a combined experimental and theoretical investigation of an unusual isotope effect on the low-energy competing H/D-loss and H2/D2-loss channels observed in the ultrafast dynamics induced by an EUV-pump pulse and probed by an infrared (IR) pulse. The relative production yields of C2D4+, C2D3+, and C2D2+ exhibit pronounced oscillations with a period of ∼50 fs as a function of the pump-probe delay, while the oscillatory patterns are less pronounced for C2H4+. By using surface hopping to model the nonadiabatic dynamics in the four lowest electronic states of the cation, we show that the enhanced oscillations in deuterated fragment yields arise from a synergy between the isotope effects on the wave packet relaxation through the network of conical intersections and on the vibrational frequencies of the cation.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"3063-3070"},"PeriodicalIF":2.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707784","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

Solvatochromism Observed in the X-ray Absorption Spectrum of Indole Dissolved in Water.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-03 Epub Date: 2025-03-21 DOI: 10.1021/acs.jpca.5c00456

Shota Tsuru, Masanari Nagasaka

{"title":"Solvatochromism Observed in the X-ray Absorption Spectrum of Indole Dissolved in Water.","authors":"Shota Tsuru, Masanari Nagasaka","doi":"10.1021/acs.jpca.5c00456","DOIUrl":"10.1021/acs.jpca.5c00456","url":null,"abstract":"Current developments in X-ray absorption spectroscopy (XAS) for liquid samples in the water window demand a rigorous understanding of the interactions between molecules or solute-solvent interactions observed in the spectra. Meanwhile, a theoretical description of such effects, in addition to inner-shell excitations, remains controversial. The controversy is mainly over whether the orbitals should be optimized in the final states or whether the orbital optimizations can be expressed by dynamic electron correlation. In the present work, we measured the XAS spectra of indole in aqueous solution at the carbon and nitrogen K-edges to compare them with those measured in the gas phase. Obvious solvatochromism was observed only in the XAS spectrum measured at the nitrogen K-edge. We then interpreted the observed solvatochromism by simulating spectra with both ΔSCF, where the orbitals were optimized in the final states, and the algebraic-diagrammatic construction through second order [ADC(2)], where the molecular orbitals optimized in the ground state were used throughout. The present results indicate that covalent interactions, such as hydrogen bonds, are the dominant causes of the solvation effects observed in XAS spectra. The present simulations with ΔSCF and ADC(2), in addition to some other reports, highlight the importance of optimizing the orbitals in the final inner-shell excited states for general inner-shell calculations with predictive accuracy.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"3020-3031"},"PeriodicalIF":2.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672871","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