International Journal of Chemical Kinetics最新文献

{"title":"Systematic study on the hydrogen abstraction reactions from oxygenated compounds by H and HO2","authors":"Hiroki Oppata,&nbsp;Daisuke Shimokuri,&nbsp;Akira Miyoshi","doi":"10.1002/kin.21761","DOIUrl":"https://doi.org/10.1002/kin.21761","url":null,"abstract":"<p>To extend the rule-based approach for hydrogen abstraction reactions from oxygenated compounds, a systematic investigation was performed to examine the reactivity of gas-phase hydrogen abstraction reactions from alkyl groups (methyl and ethyl groups) bound to oxygen atoms in five types of oxygenated compounds (alcohols, ethers, formate esters, acetate esters, and carbonate esters) by H atoms and HO₂ radicals comprehensively considering rotational conformers. Quantum chemical calculations were conducted at the CBS-QB3 level for stationary points. Rate constants were determined employing conventional transition state theory (TST). For hydrogen abstraction reactions by H, the rotational conformer distribution partition function was employed to approximate partition functions, owing to the similarity in vibrational energy-level structures among conformers. In hydrogen abstraction reactions by HO₂, the vibrational structures of transition-state (TS) conformers varied significantly due to the hydrogen bonding, leading to an inappropriate evaluation of rate constants when using the lowest-energy conformer as a representative. Therefore, the rate constants were calculated by the multi-structural TST. It was revealed that the differences in functional groups containing O atoms mainly affect the bond dissociation energies of the C–H bonds and the activation energies of hydrogen abstraction reactions only when the C atoms are adjacent to the O atoms. Additionally, it was found that hydrogen bonds formed in the TSs show minor effect on rate parameters for the overall rate constants, apart from the reduction of the pre-exponential factors for the H-abstraction reactions from the methylene position of ethyl groups. The comparison with the rate constants from previous studies showed reasonable results, indicating that the rate constants in this study, which thoroughly consider rotational conformers, can be the current best estimates.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 3","pages":"164-184"},"PeriodicalIF":1.5,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21761","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143111928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetic studies on the sulfathiazole degradation by activated persulfate with ascorbic acid and cysteine","authors":"Zaheer Khan,&nbsp;Khloud Saeed Al-Thubaiti,&nbsp;Hayat M. Albishi","doi":"10.1002/kin.21768","DOIUrl":"https://doi.org/10.1002/kin.21768","url":null,"abstract":"<p>In this study, ascorbic acid (AA) and cysteine (Cys) were used as homogeneous potassium persulfate (S₂O₈²⁻) activators. The efficiency of the S₂O₈²⁻/AA and S₂O₈²⁻/Cys systems was investigated to generate sulfate radicals (SO₄^−•) for the oxidation of sulfathiazole (STZ). The presence of AA and Cys displayed a promoting effect on the activation of S₂O₈²⁻. The results indicated that the STZ/S₂O₈²⁻ redox reaction followed pseudo-first order kinetics with respect to STZ concentrations. The oxidative degradation of STZ is accelerated by temperature, dose of S₂O₈²⁻, AA, Cys, and pH with S₂O₈²⁻/AA and/or S₂O₈²⁻/Cys systems. The degradation rates of STZ followed the order S₂O₈²⁻/AA &gt; S₂O₈²⁻/Cys &gt; S₂O₈²⁻ under similar experimental conditions. The presence of SO₄^−• and HO^• were tested with two radical scavengers, tertiary butanol (TBA) and ethanol, in which HO^• was mainly responsible for STZ degradation at higher pH. In summary, S₂O₈²⁻/AA and S₂O₈²⁻/Cys systems might provide a potentially useful technique for remediation of water contaminants.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 3","pages":"185-198"},"PeriodicalIF":1.5,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143111943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetic investigation on palladium-catalyzed carbonylation of allyl alcohol","authors":"Sunil S. Tonde,&nbsp;Kalpendra B. Rajurkar,&nbsp;Nitin S. Pagar","doi":"10.1002/kin.21767","DOIUrl":"https://doi.org/10.1002/kin.21767","url":null,"abstract":"<p>Palladium-catalyzed carbonylation of allyl alcohol to 3-butenoic acid has been investigated. A significant effect of halide promoters, <i>p</i>-tolylsulfonic acid (TsOH), water, solvents, and PPh₃ concentration activity and selectivity has been studied. Detailed kinetics of this reaction was investigated in a temperature range of 363–383 K. The influence of parameters such as stirring speed, allyl alcohol, catalyst, benzyltriethylammonium chloride (BTEAC), TsOH concentrations, and CO partial pressures on the activity and selectivity has been studied. An empirical rate equation was suggested and found to be fairly consistent with observed rate data. In addition, the activation energy and kinetic parameters were evaluated.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 3","pages":"153-163"},"PeriodicalIF":1.5,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143119249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the low-temperature oxidation chemistry of dipropyl carbonate","authors":"Lincheng Li,&nbsp;Chao Zhou,&nbsp;Guofeng Yang,&nbsp;Zhen Huang,&nbsp;Dong Han","doi":"10.1002/kin.21765","DOIUrl":"https://doi.org/10.1002/kin.21765","url":null,"abstract":"<p>Dialkyl carbonates (DACs) own an environmentally friendly synthesis route, making them potential candidates as alternative fuels. However, for DACs to be widely accepted as an alternative fuel, a comprehensive understanding of their combustion behavior is essential. Dipropyl carbonate (DPrC) represents a transition from short-chain to mid-chain carbonates, understanding its combustion behaviors holds significance in unraveling the combustion chemistry of carbonates. In this study, the oxidation of DPrC was investigated with the initial fuel mole fraction of 0.5% at three equivalence ratios of 0.5, 1.0, and 2.0 within a temperature range of 550–1100 K in a jet-stirred reactor for the first time. Gas chromatography was utilized for the quantitative detection of reactants, intermediates, and products. A detailed DPrC mechanism was first developed, and good agreements between measurements and simulations were obtained. A notable negative temperature coefficient (NTC) behavior was first observed in the oxidation of DACs. Such NTC phenomenon occurred at fuel-lean conditions in the temperature range of 620–660 K, while only a weak low-temperature consumption was observed at the stoichiometric condition. Kinetic modeling studies showed that this unique low-temperature chemistry of DPrC can be attributed to the differences in the RO₂ isomerization reactions between DPrC and short-chain DACs. The RO₂ isomerization via a six-member ring transition state could happen in DPrC oxidation but not in dimethyl carbonate and diethyl carbonate oxidation, due to the different fuel molecular structure. Therefore, the subsequent reaction pathways via QOOH → O₂QOOH → HO₂Q = O + OH → OQ = O + OH were promoted and two OH radicals were released in this process. Moreover, it is conceivable that mid or long-chain DACs could also exhibit an NTC phenomenon due to the increased potential for RO₂ isomerization via a six- or seven-member ring transition state, thereby increasing the likelihood of RO₂ isomerization occurrence.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 2","pages":"139-149"},"PeriodicalIF":1.5,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143118540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transitory sensitivity in automatic chemical kinetic mechanism analysis","authors":"Matthew S. Johnson,&nbsp;Charles J. McGill,&nbsp;William H. Green","doi":"10.1002/kin.21766","DOIUrl":"https://doi.org/10.1002/kin.21766","url":null,"abstract":"<p>Detailed chemical kinetic mechanisms are necessary for resolving many important chemical processes. As the chemistry of smaller molecules has become better grounded and quantum chemistry calculations have become cheaper, kineticists have become interested in constructing progressively larger kinetic mechanisms to model increasingly complex chemical processes. These large kinetic mechanisms prove incredibly difficult to refine and time-consuming to interpret. Traditional sensitivity analysis on a large mechanism can range from inconvenient to practically impossible without special techniques to reduce the computational cost. We first present a new time-local sensitivity analysis we term transitory sensitivity analysis. Transitory sensitivity analysis is demonstrated in an example to accurately identify traditionally sensitive reactions at an 18,000x speed up over traditional sensitivities. By fusing transitory sensitivity analysis with more traditional time-local branching, pathway, and cluster analyses, we develop an algorithm for efficient automatic mechanism analysis. This automatic mechanism analysis at a time point is able to identify the reactions a target is most sensitive to using transitory sensitivity analysis and then propose hypotheses why the reaction might be sensitive using branching, pathway, and cluster analyses. We implement these algorithms within the reaction mechanism simulator (RMS) package, which enables us to report the automatic mechanism analysis results in highly readable text formats and in molecular flux diagrams.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 2","pages":"125-138"},"PeriodicalIF":1.5,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21766","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143117765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macrokinetics of ammonium sulfite oxidation inhibited by sodium thiosulfate in wet ammonium flue gas desulfurization","authors":"Jian Peng,&nbsp;Wen Yao,&nbsp;Peichao Lian","doi":"10.1002/kin.21764","DOIUrl":"https://doi.org/10.1002/kin.21764","url":null,"abstract":"<p>The oxidation of ammonium sulfite must be inhibited to improve the economy and cycle performance of the ammonia flue gas desulfurization process. A stirred bubbling reactor was used to investigate the macrokinetics of oxidation inhibition of ammonium sulfite by sodium thiosulfate in wet ammonia desulfurization. The effects of initial <span></span><math>\u0000 <semantics>\u0000 <msubsup>\u0000 <mi>SO</mi>\u0000 <mn>3</mn>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 <mo>−</mo>\u0000 </mrow>\u0000 </msubsup>\u0000 <annotation>${rm SO}^{2-}_{3}$</annotation>\u0000 </semantics></math> concentration, Na₂S₂O₃ concentration, pH value, gas flow rate, and temperature on the oxidation rate were discussed. The results show that the apparent activation energy of the reaction is 37.3 kJ/mol. The macrokinetics equation of sodium thiosulfate inhibiting sulfite oxidation in the ammonia desulfurization process was established. Combined with the kinetic model, it is inferred that the rate of sodium thiosulfate inhibiting ammonium sulfite oxidation is controlled by the intrinsic chemical reaction. The results can provide a reference for the regeneration of ammonium sulfite in the wet ammonia desulfurization process.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 2","pages":"117-124"},"PeriodicalIF":1.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143116437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atmospheric chemistry of (Z)-CF2HCF=CHCl: Kinetics and products of reaction with Cl atoms and OH radicals","authors":"Mads Peter Sulbaek Andersen,&nbsp;Josefine Ellerup Borcher,&nbsp;Ole John Nielsen","doi":"10.1002/kin.21763","DOIUrl":"https://doi.org/10.1002/kin.21763","url":null,"abstract":"<p>Long path length FTIR-smog chamber techniques were used to study the title reactions in 650 Torr of N₂, oxygen, or air diluent at 296 ± 3 K. Values of <i>k</i>(Cl + (<i>Z</i>)-CF₂HCF = CHCl)═(6.6 ± 0.7) × 10⁻¹¹ and <i>k</i>(OH + (<i>Z</i>)-CF₂HCF═CHCl)═(4.1 ± 0.7) × 10⁻¹² cm³ molecule⁻¹ s⁻¹ were measured. The IR spectrum of (<i>Z</i>)-CF₂HCF═CHCl is reported. The atmospheric lifetime of (<i>Z</i>)-CF₂HCF═CHCl is determined by the reaction with OH and is approximately 2.8 days. Reaction of (<i>Z</i>)-CF₂HCF═CHCl with Cl atoms gives HC(O)Cl and CF₂HC(O)F as major primary products. Under environmental conditions, the OH radical initiated oxidation gives CF₂HC(O)F and HC(O)Cl in yields of (98 ± 8)% and (100 ± 4)%, respectively. Accounting for non-uniform horizontal and vertical mixing leads to a 100-year time-horizon global warming potential value for (<i>Z</i>)-CF₂HCF═CHCl of essentially zero.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 2","pages":"108-116"},"PeriodicalIF":1.5,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21763","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143113229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Species selection for automatic chemical kinetic mechanism generation","authors":"Matthew S. Johnson,&nbsp;Hao-Wei Pang,&nbsp;Mengjie Liu,&nbsp;William H. Green","doi":"10.1002/kin.21762","DOIUrl":"https://doi.org/10.1002/kin.21762","url":null,"abstract":"<p>Many important chemical kinetic systems require detailed chemical kinetic models to resolve. These detailed kinetic models can involve thousands of species and hundreds of thousands of chemical reactions, making them difficult to construct by hand. Modern automatic mechanism generation algorithms can mostly be divided into two classes: rule and rate based. Rule-based generators choose species based on user defined constraints on species and reaction classes. Rate-based generators generate a much larger set of potentially important species and reactions and then choose which ones to add based on running simulations of species and reactions deemed important and calculating the flux to potentially important species. In principle, the latter is preferable, as it requires the user to make far fewer assumptions about what is important in the system. However, while the effectiveness of the rate-based approach has been demonstrated in a wide variety of systems, it has also been demonstrated to have difficulty picking up important low-flux chemistries. Here we present a discussion of the challenges associated with rate-based mechanism generation and new algorithms that are able to efficiently mitigate these challenges improving species selection during mechanism generation in a set of case studies.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 2","pages":"93-107"},"PeriodicalIF":1.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21762","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143118913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decomposition of \u0000 \u0000 \u0000 \u0000 CH\u0000 3\u0000 \u0000 \u0000 NH\u0000 2\u0000 \u0000 \u0000 ${rm CH}_3{rm NH}_2$\u0000 : Implications for \u0000 \u0000 \u0000 \u0000 CH\u0000 x\u0000 \u0000 /\u0000 \u0000 NH\u0000 y\u0000 \u0000 \u0000 ${rm CH}_{rm {it x}}/{rm NH}_{rm {it y}}$\u0000 radical–radical reactions","authors":"Peter Glarborg,&nbsp;Maria U. Alzueta","doi":"10.1002/kin.21760","DOIUrl":"https://doi.org/10.1002/kin.21760","url":null,"abstract":"&lt;p&gt;Experiments on methylamine (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CH&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;NH&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;${rm CH}_3{rm NH}_2$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) decomposition in shock tubes, flow reactors, and batch reactors have been re-examined to improve the understanding of hydrocarbon/amine interactions and constrain rate constants for &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CH&lt;/mi&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${rm CH}_{ x}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; + &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;NH&lt;/mi&gt;\u0000 &lt;mi&gt;y&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${rm NH}_{ y}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; reactions. In high-temperature shock tube experiments, the rapid thermal dissociation of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CH&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;NH&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;${rm CH}_3{rm NH}_2$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; provides a fairly clean source of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CH&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${rm CH}_3$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;NH&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${rm NH}_2$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; radicals, allowing an assessment of reactions of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CH&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${rm CH}_3$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; with &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;NH&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${rm NH}_2$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and NH. At the lower temperatures in batch and flow reactors, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 ","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 1","pages":"77-90"},"PeriodicalIF":1.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21760","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142707853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Force training neural network potential energy surface models","authors":"Christian Devereux,&nbsp;Yoona Yang,&nbsp;Carles Martí,&nbsp;Judit Zádor,&nbsp;Michael S. Eldred,&nbsp;Habib N. Najm","doi":"10.1002/kin.21759","DOIUrl":"10.1002/kin.21759","url":null,"abstract":"<p>Machine learned chemical potentials have shown great promise as alternatives to conventional computational chemistry methods to represent the potential energy of a given atomic or molecular system as a function of its geometry. However, such potentials are only as good as the data they are trained on, and building a comprehensive training set can be a costly process. Therefore, it is important to extract as much information from training data as possible without further increasing the computational cost. One way to accomplish this is by training on molecular forces in addition to energies. This allows for three additional labels per atom within the molecule. Here we develop a neural network potential energy surface for studying a hydrogen transfer reaction between two isomers of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>C</mi>\u0000 <mn>5</mn>\u0000 </msub>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mn>5</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>${mathrm{C}}_5{mathrm{H}}_5$</annotation>\u0000 </semantics></math>. We show that, for a much smaller training set, force training not only improves the accuracy of the model compared to only training on energies, but also provides more accurate and smoother first and second derivatives that are crucial to run dynamics and extract vibrational frequencies in the context of transition-state theory. We also demonstrate the importance of choosing the proper force to energy weight ratio for the loss function to minimize the model test error.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 1","pages":"59-76"},"PeriodicalIF":1.5,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}