The Journal of Physical Chemistry A最新文献_第7页

Exploring Nanocluster Potential Energy Surfaces via Deep Reinforcement Learning: Strategies for Global Minimum Search. 通过深度强化学习探索纳米簇势能面：全局最小搜索策略。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 Epub Date: 2024-10-13 DOI: 10.1021/acs.jpca.4c04416

Rajesh K Raju

{"title":"Exploring Nanocluster Potential Energy Surfaces via Deep Reinforcement Learning: Strategies for Global Minimum Search.","authors":"Rajesh K Raju","doi":"10.1021/acs.jpca.4c04416","DOIUrl":"10.1021/acs.jpca.4c04416","url":null,"abstract":"The search for global minimum (GM) configurations in nanoclusters is complicated by intricate potential energy landscapes replete with numerous local minima. The complexity of these landscapes escalates with increasing cluster size and compositional diversity. Evolutionary algorithms, such as genetic algorithms, are hampered by slow convergence rates and a propensity for prematurely settling on suboptimal solutions. Likewise, the basin hopping technique faces difficulties in navigating these complex landscapes effectively, particularly at larger scales. These challenges highlight the need for more sophisticated methodologies to efficiently scan the potential energy surfaces of nanoclusters. In response, our research has developed a novel deep reinforcement learning (DRL) framework specifically designed to explore the potential energy surfaces (PES) of nanoclusters, aiming to identify the GM configurations along with other low-energy states. This study demonstrates the framework's effectiveness in managing various nanocluster types, including both mono- and multimetallic compositions, and its proficiency in navigating complex energy landscapes. The model is characterized by remarkable adaptability and sustained efficiency, even as cluster sizes and feature vector dimensions increase. The demonstrated adaptability of DRL in this context underscores its considerable potential in materials science, particularly for the efficient discovery and optimization of novel nanomaterials. To the best of our knowledge, this is the first DRL framework designed for the GM search in nanoclusters, representing a significant innovation in the field.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11514025/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453490","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

Facilitating Absorption Spectroscopy of Strongly Absorbing Fluids: A High-Throughput Approach 促进强吸收流体的吸收光谱分析：高通量方法

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 DOI: 10.1021/acs.jpca.4c0490210.1021/acs.jpca.4c04902

Fabian Eller, and , Eva M. Herzig*,

{"title":"Facilitating Absorption Spectroscopy of Strongly Absorbing Fluids: A High-Throughput Approach","authors":"Fabian Eller,  and , Eva M. Herzig*, ","doi":"10.1021/acs.jpca.4c0490210.1021/acs.jpca.4c04902","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c04902https://doi.org/10.1021/acs.jpca.4c04902","url":null,"abstract":"Measuring absorption spectra of strongly absorbing solutions is usually only possible by diluting the solution. However, the absorption spectra can be heavily influenced by concentration-dependent interactions, so dilution leads to misleading results. To enable reliable absorption measurements of concentrated solutions, we introduce in this work thinning fluid film spectroscopy (TFFS), a simple and highly automatable method. We present three exemplary measurement modes of TFFS suitable for many different applications and validate the TFFS measurements with control data obtained in specialized, low optical path length cuvettes. Additionally, we compare the suitability of the different measurement modes over a broad concentration range and demonstrate the automation possibilities with a spectroscopy robot. Beyond this automated approach for highly efficient and high-throughput lab work, we also show the possibility of direct integration into production systems with an in-line setup, which can be incorporated into a variety of pipe systems. The TFFS method is not limited to samples from material science but can be transferred to a broad variety of research and industry fields, including proteins, food, and pharmaceuticals or also agriculture and forensics.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608738","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

Stochastic Resolution of Identity to CC2 for Large Systems: Ground State and Triplet Excitation Energy Calculations. 随机解决大系统的 CC2 特性问题：基态和三重激发能量计算。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 Epub Date: 2024-10-11 DOI: 10.1021/acs.jpca.4c04264

Chongxiao Zhao, Joonho Lee, Wenjie Dou

{"title":"Stochastic Resolution of Identity to CC2 for Large Systems: Ground State and Triplet Excitation Energy Calculations.","authors":"Chongxiao Zhao, Joonho Lee, Wenjie Dou","doi":"10.1021/acs.jpca.4c04264","DOIUrl":"10.1021/acs.jpca.4c04264","url":null,"abstract":"An implementation of stochastic resolution of identity to the CC2 (sRI-CC2) ground state energy followed by triplet excitation energy calculations is presented. A set of stochastic orbitals is introduced to further decouple the expensive 4-index electron repulsion integrals on the basis of RI approximation. A Laplace transformation of the orbital energy difference denominators into numerical summations is adopted to obtain a third-order overall scaling. We select a series of hydrogen dimer chains with nearly thousands of electrons, as well as some other molecules, for sRI-CC2 energies and test the accuracy and time consumption in comparison with those of RI-CC2. Our sRI-CC2 results reproduce a modest agreement with the RI-CC2 in Q-Chem program package and it allows a steep scaling reduction from O(N5) to O(N3). Besides, the unrestricted sRI-CC2 calculations also fit well with the restricted results. Thus, our sRI-CC2 implementation of ground state energy and triplet excitation energy provides a cost-efficient alternative approach, especially for some large-sized systems.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398731","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 Association and Reactivity of the Pyridine Dimer Cation. 吡啶二聚阳离子的分子关联和反应活性。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 Epub Date: 2024-10-16 DOI: 10.1021/acs.jpca.4c04912

Amol Tagad, G Naresh Patwari

引用次数: 0

Molecular Structure Theory without the Born-Oppenheimer Approximation: Rotationless Vibrational States of LiH. 无玻恩-奥本海默近似的分子结构理论：LiH 的无旋转振动态。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 Epub Date: 2024-10-12 DOI: 10.1021/acs.jpca.4c04510

Saeed Nasiri, Sergiy Bubin, Monika Stanke, Ludwik Adamowicz

引用次数: 0

Computational Mechanistic Analysis of the Formation of the Magnesium Silicate Monomers MgSiO₃ and Mg₂SiO₄. 硅酸镁单体 MgSiO3 和 Mg2SiO4 形成的计算机理分析。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 Epub Date: 2024-10-14 DOI: 10.1021/acs.jpca.4c05680

Athena R Flint, Ryan C Fortenberry

{"title":"Computational Mechanistic Analysis of the Formation of the Magnesium Silicate Monomers MgSiO3 and Mg2SiO4.","authors":"Athena R Flint, Ryan C Fortenberry","doi":"10.1021/acs.jpca.4c05680","DOIUrl":"10.1021/acs.jpca.4c05680","url":null,"abstract":"Silicate grains comprise a large fraction of cosmic dust, motivating a need to understand how they form. The current body of work on silicates generally reflects the abundance of silicate grains, yet models for their formation often do not consider silicate chemistry on the smallest scale, which can form species available for dust grain nucleation processes. In order to expand upon previous attempts to bridge this gap in silicate chemistry, novel gas-phase reaction pathways for the magnesium silicate monomers enstatite (MgSiO3) and forsterite (Mg2SiO4) from MgH, H2O, and SiO are presently computed using highly accurate quantum chemical calculations. MgSiO3 and Mg2SiO4 form through a series of reactions that initially excludes silicon addition, creating the elusive species MgOH and Mg2O prior to further reaction. The formation of the two silicate monomers is expected to be efficient with the primary bottleneck being the amount of MgH available for reaction. The addition of these reactions to cosmic chemical networks will add further clarity to the processes that govern dust formation, most significantly for those occurring within stellar outflows of asymptotic giant branch stars.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453483","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

Thawed Gaussian Wavepacket Dynamics with Δ-Machine-Learned Potentials. 解冻高斯波包动力学与 Δ 机器学习势能

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 Epub Date: 2024-10-11 DOI: 10.1021/acs.jpca.4c02979

Rami Gherib, Ilya G Ryabinkin, Scott N Genin

{"title":"Thawed Gaussian Wavepacket Dynamics with Δ-Machine-Learned Potentials.","authors":"Rami Gherib, Ilya G Ryabinkin, Scott N Genin","doi":"10.1021/acs.jpca.4c02979","DOIUrl":"10.1021/acs.jpca.4c02979","url":null,"abstract":"A method for performing variable-width (thawed) Gaussian wavepacket (GWP) variational dynamics on machine-learned potentials is presented. Instead of fitting the potential energy surface (PES), the anharmonic correction to the global harmonic approximation (GHA) is fitted using kernel ridge regression─this is a Δ-machine learning approach. The training set consists of energy differences between ab initio electronic energies and values given by the GHA. The learned potential is subsequently used to propagate a single thawed GWP by using the time-dependent variational principle to compute the autocorrelation function, which provides direct access to vibronic spectra via its Fourier transform. We applied the developed method to simulate the photoelectron spectrum of ammonia and found excellent agreement between theoretical and experimental spectra. We show that fitting the anharmonic corrections requires a smaller training set as compared to fitting total electronic energies. We also demonstrate that our approach allows to reduce the dimensionality of the nuclear space used to scan the PES when constructing the training set. Thus, only the degrees of freedom associated with large-amplitude motions need to be treated with Δ-machine learning, which paves a way for reliable simulations of vibronic spectra of large floppy molecules.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405741","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

Ultrafast Charge Separation Driven by Solvation-Coupled Intramolecular Torsion. 溶解耦合分子内扭转驱动的超快电荷分离。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 Epub Date: 2024-10-10 DOI: 10.1021/acs.jpca.4c05149

Yang Li, Lin Ma, Jiang-Yang Shao, Zhuoran Kuang, Jiawen Zhang, Yan Wan, Yu-Wu Zhong, Hongmei Zhao

{"title":"Ultrafast Charge Separation Driven by Solvation-Coupled Intramolecular Torsion.","authors":"Yang Li, Lin Ma, Jiang-Yang Shao, Zhuoran Kuang, Jiawen Zhang, Yan Wan, Yu-Wu Zhong, Hongmei Zhao","doi":"10.1021/acs.jpca.4c05149","DOIUrl":"10.1021/acs.jpca.4c05149","url":null,"abstract":"Photoinduced intramolecular charge separation in a pyrene- and triarylamine-based donor-acceptor dyad was studied by polarization-dependent femtosecond time-resolved transient absorption (TA) spectroscopy in polar solvents. Photoexcitation forms an excited state with charge transfer (CT) character due to the intrinsic electronic coupling between the triarylamine and pyrene groups, resulting in ultrafast charge separation (CS) in polar solvents. TA measurements reveal a correlation between the rate of CS and solvation dynamics, which implies that solvation is involved in the CS reaction. In addition, polarization-dependent TA spectroscopy was devoted to tracking the ultrafast anisotropy evolution of the cationic absorption band, which is attributed to intramolecular torsional motion and is proposed to be coupled to diffusive orientational solvent modes. The results therefore reveal that the evolution of the CT state in the condensed phase is driven by solvation-coupled excited-state structural relaxation. In other words, intramolecular torsional motion is directly confirmed to be involved in the reaction coordinate of the CS reaction in a strongly coupled donor-acceptor dyad.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453436","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

Electronic Structures and Spectra of Donor-Acceptor Conjugated Oligomers. 供体-受体共轭低聚物的电子结构和光谱。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 Epub Date: 2024-10-11 DOI: 10.1021/acs.jpca.4c04458

Kiet A Nguyen, Ruth Pachter, Lauren M Loftus, Gongyi Hong, Paul N Day, Jason D Azoulay, Tod A Grusenmeyer

{"title":"Electronic Structures and Spectra of Donor-Acceptor Conjugated Oligomers.","authors":"Kiet A Nguyen, Ruth Pachter, Lauren M Loftus, Gongyi Hong, Paul N Day, Jason D Azoulay, Tod A Grusenmeyer","doi":"10.1021/acs.jpca.4c04458","DOIUrl":"10.1021/acs.jpca.4c04458","url":null,"abstract":"Narrow band gap donor-acceptor conjugated polymers present excellent paradigms in photonics and optoelectronics due to their chemical tunability, correlated electronic structures, and tunable open-shell electronic configurations. However, rational design for enhancing the properties of these molecular systems remains challenging. In this study, we employed density functional theory (DFT) calculations to investigate prototypical narrow band gap donor-acceptor conjugated oligomers, consisting of alternating cyclopentadithiophene (CPDT) donors paired with benzothiadiazole (BT), benzoselenadiazole (BSe), benzobisthiadiazole (BBT), and thiadiazoloquinoxaline (TQ) acceptors. Analyses of structures, singlet-triplet gaps, and absorption spectra of oligomers with up to ten repeat units have shown that when incorporating the BT, BSe, and TQ acceptors, the backbone curvature resulted in spiral structures that were energetically favored over their linear counterparts, causing differences in the calculated circular dichroism spectra. Oligomers with BBT-based acceptors preferred, however, a linear geometry, consistent with an open-shell electronic structure. Calculated singlet-triplet splittings demonstrated the importance of long chains and specific structures for consistency with the experiment, while effects of the solvent were also quantified. Based on the predicted low-energy conformations, one-photon absorption spectra for the considered oligomers have shown that using the Tamm-Dancoff approximation within time-dependent DFT for the large systems offers good agreement with the first absorption maxima in measured experimental spectra, thus validating the method for large donor-acceptor oligomers. Natural transition orbital analyses provided insights into the excited-state characteristics. Two-photon absorption maxima were accurately predicted, but the cross-sections were overestimated or underestimated, as dependent on the level of theory employed, to be addressed in future work.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398727","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

Multiphoton Dissociative Ionization of Gas-Phase Styrene. 气相苯乙烯的多光子离解电离。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-10-24 Epub Date: 2024-10-14 DOI: 10.1021/acs.jpca.4c05621

Nihar Ranjan Behera, Saroj Barik, Saurav Dutta, Rajesh Kumar Kushawaha, Sajeev Y, Aravind G

引用次数: 0