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Shi Z, Lele AD, Jasper AW, Klippenstein SJ, Ju Y. Quasi-Classical Trajectory Calculation of Rate Constants Using an Ab Initio Trained Machine Learning Model (aML-MD) with Multifidelity Data. J Phys Chem A 2024. [PMID: 38642065 DOI: 10.1021/acs.jpca.4c00750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2024]
Abstract
Machine learning (ML) provides a great opportunity for the construction of models with improved accuracy in classical molecular dynamics (MD). However, the accuracy of a ML trained model is limited by the quality and quantity of the training data. Generating large sets of accurate ab initio training data can require significant computational resources. Furthermore, inconsistent or incompatible data with different accuracies obtained using different methods may lead to biased or unreliable ML models that do not accurately represent the underlying physics. Recently, transfer learning showed its potential for avoiding these problems as well as for improving the accuracy, efficiency, and generalization of ML models using multifidelity data. In this work, ab initio trained ML-based MD (aML-MD) models are developed through transfer learning using DFT and multireference data from multiple sources with varying accuracy within the Deep Potential MD framework. The accuracy of the force field is demonstrated by calculating rate constants for the H + HO2 → H2 + 3O2 reaction using quasi-classical trajectories. We show that the aML-MD model with transfer learning can accurately predict the rate constants while reducing the computational cost by more than five times compared to the use of more expensive quantum chemistry training data sets. Hence, the aML-MD model with transfer learning shows great potential in using multifidelity data to reduce the computational cost involved in generating the training set for these potentials.
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Affiliation(s)
- Zhiyu Shi
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Aditya Dilip Lele
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Yiguang Ju
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States
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2
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Qian Y, Roy TK, Jasper AW, Sojdak CA, Kozlowski MC, Klippenstein SJ, Lester MI. Isomer-resolved unimolecular dynamics of the hydroperoxyalkyl intermediate (•QOOH) in cyclohexane oxidation. Proc Natl Acad Sci U S A 2024; 121:e2401148121. [PMID: 38602914 PMCID: PMC11032462 DOI: 10.1073/pnas.2401148121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 03/08/2024] [Indexed: 04/13/2024] Open
Abstract
The oxidation of cycloalkanes is important in the combustion of transportation fuels and in atmospheric secondary organic aerosol formation. A transient carbon-centered radical intermediate (•QOOH) in the oxidation of cyclohexane is identified through its infrared fingerprint and time- and energy-resolved unimolecular dissociation dynamics to hydroxyl (OH) radical and bicyclic ether products. Although the cyclohexyl ring structure leads to three nearly degenerate •QOOH isomers (β-, γ-, and δ-QOOH), their transition state (TS) barriers to OH products are predicted to differ considerably. Selective characterization of the β-QOOH isomer is achieved at excitation energies associated with the lowest TS barrier, resulting in rapid unimolecular decay to OH products that are detected. A benchmarking approach is employed for the calculation of high-accuracy stationary point energies, in particular TS barriers, for cyclohexane oxidation (C6H11O2), building on higher-level reference calculations for the smaller ethane oxidation (C2H5O2) system. The isomer-specific characterization of β-QOOH is validated by comparison of experimental OH product appearance rates with computed statistical microcanonical rates, including significant heavy-atom tunneling, at energies in the vicinity of the TS barrier. Master-equation modeling is utilized to extend the results to thermal unimolecular decay rate constants at temperatures and pressures relevant to cyclohexane combustion.
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Affiliation(s)
- Yujie Qian
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA19104-6323
| | - Tarun Kumar Roy
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA19104-6323
| | - Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL60439
| | | | - Marisa C. Kozlowski
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA19104-6323
| | | | - Marsha I. Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA19104-6323
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3
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Frenklach M, Jasper AW, Mebel AM. Phenalenyl growth reactions and implications for prenucleation chemistry of aromatics in flames. Phys Chem Chem Phys 2024. [PMID: 38587503 DOI: 10.1039/d4cp00096j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
The energetics and kinetics of phenalene and phenalenyl growth reactions were studied theoretically. Rate constants of phenalene and phenalenyl H-abstraction and C2H2 addition to the formed radicals were evaluated through quantum-chemical and rate-theory calculations. The obtained values, assigned to all π radicals, were tested in deterministic and kinetic Monte Carlo simulations of aromatics growth under conditions of laminar premixed flames. Kekulé and non-Kekulé structures of the polycyclic aromatic hydrocarbons (PAHs) evolving in the stochastic simulations were identified by on-the-fly constrained optimization. The numerical results demonstrated an increased PAH growth and qualitatively reproduced experimental observations of Homann and co-workers of non-decaying PAH concentrations with nearly equal abundances of even and odd carbon-atom PAHs. The analysis revealed that the PAH growth proceeds via alternating and sterically diverse acetylene and methyl HACA additions. The rapid and diverse spreading in the PAH population supports a nucleation model as PAH dimerization, assisted by the non-equilibrium phenomena, forming planar aromatics first and then transitioning to the PAH-PAH stacking with size.
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Affiliation(s)
- Michael Frenklach
- Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA.
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA.
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, USA.
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4
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Bindra JK, Niklas J, Jeong Y, Jasper AW, Kretzschmar M, Kern J, Utschig LM, Poluektov OG. Coherences of Photoinduced Electron Spin Qubit Pair States in Photosystem I. J Phys Chem B 2023; 127:10108-10117. [PMID: 37980604 DOI: 10.1021/acs.jpcb.3c06658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
This publication presents the first comprehensive experimental study of electron spin coherences in photosynthetic reaction center proteins, specifically focusing on photosystem I (PSI). The ultrafast electron transfer in PSI generates spin-correlated radical pairs (SCRPs), which are entangled spin pairs formed in well-defined spin states (Bell states). Since their discovery in our group in the 1980s, SCRPs have been extensively used to enhance our understanding of structure-function relationships in photosynthetic proteins. More recently, SCRPs have been utilized as tools for quantum sensing. Electron spin decoherence poses a significant challenge in realizing practical applications of electron spin qubits, particularly the creation of quantum entanglement between multiple electron spins. This work is focused on the systematic characterization of decoherence in SCRPs of PSI. These decoherence times were measured as electron spin echo decay times, termed phase memory times (TM), at various temperatures. Decoherence was recorded on both transient SCRP states P700+A1- and thermalized states. Our study reveals that TM exhibits minimal dependence on the biological species, biochemical treatment, and paramagnetic species. The analysis indicates that nuclear spin diffusion and instantaneous diffusion mechanisms alone cannot explain the observed decoherence. As a plausible explanation we discuss the assumption that the low-temperature dynamics of methyl groups in the protein surrounding the unpaired electron spin centers is the main factor governing the loss of the spin coherence in PSI.
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Affiliation(s)
- Jasleen K Bindra
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Jens Niklas
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Yeonjun Jeong
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Moritz Kretzschmar
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Lisa M Utschig
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Oleg G Poluektov
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
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5
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Chen TY, Steinmetz SA, Patterson BD, Jasper AW, Kliewer CJ. Direct observation of coherence transfer and rotational-to-vibrational energy exchange in optically centrifuged CO 2 super-rotors. Nat Commun 2023; 14:3227. [PMID: 37270647 DOI: 10.1038/s41467-023-38873-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/18/2023] [Indexed: 06/05/2023] Open
Abstract
Optical centrifuges are laser-based molecular traps that can rotationally accelerate molecules to energies rivalling or exceeding molecular bond energies. Here we report time and frequency-resolved ultrafast coherent Raman measurements of optically centrifuged CO2 at 380 Torr spun to energies beyond its bond dissociation energy of 5.5 eV (Jmax = 364, Erot = 6.14 eV, Erot/kB = 71, 200 K). The entire rotational ladder from J = 24 to J = 364 was resolved simultaneously which enabled a more accurate measurement of the centrifugal distortion constants for CO2. Remarkably, coherence transfer was directly observed, and time-resolved, during the field-free relaxation of the trap as rotational energy flowed into bending-mode vibrational excitation. Vibrationally excited CO2 (ν2 > 3) was observed in the time-resolved spectra to populate after 3 mean collision times as a result of rotational-to-vibrational (R-V) energy transfer. Trajectory simulations show an optimal range of J for R-V energy transfer. Dephasing rates for molecules rotating up to 5.5 times during one collision were quantified. Very slow decays of the vibrational hot band rotational coherences suggest that they are sustained by coherence transfer and line mixing.
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Affiliation(s)
- Timothy Y Chen
- Sandia National Laboratories, Livermore, 94550, CA, USA
- Applied Materials, Inc., Santa Clara, 95051, CA, USA
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6
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Selby TM, Goulay F, Soorkia S, Ray A, Jasper AW, Klippenstein SJ, Morozov AN, Mebel AM, Savee JD, Taatjes CA, Osborn DL. Radical-Radical Reactions in Molecular Weight Growth: The Phenyl + Propargyl Reaction. J Phys Chem A 2023; 127:2577-2590. [PMID: 36905386 DOI: 10.1021/acs.jpca.2c08121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
The mechanism for hydrocarbon ring growth in sooting environments is still the subject of considerable debate. The reaction of phenyl radical (C6H5) with propargyl radical (H2CCCH) provides an important prototype for radical-radical ring-growth pathways. We studied this reaction experimentally over the temperature range of 300-1000 K and pressure range of 4-10 Torr using time-resolved multiplexed photoionization mass spectrometry. We detect both the C9H8 and C9H7 + H product channels and report experimental isomer-resolved product branching fractions for the C9H8 product. We compare these experiments to theoretical kinetics predictions from a recently published study augmented by new calculations. These ab initio transition state theory-based master equation calculations employ high-quality potential energy surfaces, conventional transition state theory for the tight transition states, and direct CASPT2-based variable reaction coordinate transition state theory (VRC-TST) for the barrierless channels. At 300 K only the direct adducts from radical-radical addition are observed, with good agreement between experimental and theoretical branching fractions, supporting the VRC-TST calculations of the barrierless entrance channel. As the temperature is increased to 1000 K we observe two additional isomers, including indene, a two-ring polycyclic aromatic hydrocarbon, and a small amount of bimolecular products C9H7 + H. Our calculated branching fractions for the phenyl + propargyl reaction predict significantly less indene than observed experimentally. We present further calculations and experimental evidence that the most likely cause of this discrepancy is the contribution of H atom reactions, both H + indenyl (C9H7) recombination to indene and H-assisted isomerization that converts less stable C9H8 isomers into indene. Especially at low pressures typical of laboratory investigations, H-atom-assisted isomerization needs to be considered. Regardless, the experimental observation of indene demonstrates that the title reaction leads, either directly or indirectly, to the formation of the second ring in polycyclic aromatic hydrocarbons.
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Affiliation(s)
- Talitha M Selby
- Department of Mathematics and Natural Sciences, University of Wisconsin-Milwaukee, West Bend, Wisconsin 53095, United States
| | - Fabien Goulay
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Satchin Soorkia
- Institut des Sciences Moléculaires d'Orsay, Université Paris-Saclay, CNRS, F-91405 Orsay, France
| | - Amelia Ray
- Department of Chemistry, University of Wisconsin-Parkside, Kenosha, Wisconsin 53144, United States
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Alexander N Morozov
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - John D Savee
- KLA Corporation, Milpitas, California 95035, United States
| | - Craig A Taatjes
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551, United States
| | - David L Osborn
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551, United States
- Department of Chemical Engineering, University of California, Davis, Davis, California 95616, United States
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7
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Babikov D, Burke MP, Casavecchia P, Green WH, Grinberg Dana A, Guo H, Heard DE, Heathcote D, Hochlaf M, Jasper AW, Klippenstein SJ, Lester MI, Martí C, Mebel AM, Mullin AS, Nguyen TL, Olzmann M, Orr-Ewing AJ, Osborn DL, Robertson PA, Robinson MS, Shannon RJ, Shiels OJ, Suits AG, Taatjes CA, Troe J, Xu X, You X, Zhang F, Zhang RM, Zádor J. Collisional energy transfer: general discussion. Faraday Discuss 2022; 238:121-143. [PMID: 36200457 DOI: 10.1039/d2fd90048c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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8
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Yang Z, Doddipatla S, He C, Goettl SJ, Kaiser RI, Jasper AW, Gomes ACR, Galvão BRL. Can third-body stabilisation of bimolecular collision complexes in cold molecular clouds happen? Mol Phys 2022. [DOI: 10.1080/00268976.2022.2134832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Zhenghai Yang
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, HI, USA
| | | | - Chao He
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, HI, USA
| | - Shane J. Goettl
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, HI, USA
| | - Ralf I. Kaiser
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, HI, USA
| | - Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
| | - Alexandre C. R. Gomes
- Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Minas Gerais, Brazil
| | - Breno R. L. Galvão
- Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Minas Gerais, Brazil
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9
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Gomes ACR, Rocha CMR, Jasper AW, Galvão BRL. Formation of phosphorus monoxide through the [Formula: see text] reaction. J Mol Model 2022; 28:259. [PMID: 35978224 DOI: 10.1007/s00894-022-05242-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 07/19/2022] [Indexed: 11/24/2022]
Abstract
Phosphorus is a key and vital element for a diverse set of important biological molecules, being indispensable for life as we know. A deeper comprehension of its role in astrochemistry and atmospheric chemistry may aid in finding answers to how this element became available on Earth. The PO molecule is one of the main reservoirs of phosphorus in the interstellar medium (ISM), and a better understanding of the mechanisms and rate coefficients for its formation in the ISM is important for modelling its abundances. In this work, we perform multireference configuration interaction calculations on the formation of PO via the [Formula: see text] reaction, analyzing its potential energy surface and rate coefficients for the global reaction on both doublet and quartet states. We also perform DFT (M06-2X) and CCSD(T) calculations, in order to compare the results. We found that the OPO system possesses a high multiconfigurational character, making DFT and CCSD methodologies not suitable for its potential energy landscape calculation. The rate coefficients have been calculated using the master equation system solver (MESS) package, and the results compared to recent experimental data. It is shown that the quartet state contributes for temperatures higher than 700K. The computed rate coefficient can be described by a modified Arrhenius equation [[Formula: see text]] with [Formula: see text], [Formula: see text] and [Formula: see text] K.
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Affiliation(s)
- Alexandre C R Gomes
- Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Av. Amazonas 5253, 30421-169, Belo Horizonte, Minas Gerais, Brazil
| | - Carlos M R Rocha
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA, Leiden, The Netherlands
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Breno R L Galvão
- Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Av. Amazonas 5253, 30421-169, Belo Horizonte, Minas Gerais, Brazil
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10
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Aerssens J, Burke MP, Cavallotti C, Green NJB, Green WH, Guo H, Heard D, Hochlaf M, Jasper AW, Klippenstein SJ, Kuwata KT, Lawrence JE, Mebel AM, Mullin AS, Nguyen TL, Olzmann M, Osborn DL, Pfeifle M, Plane JMC, Robertson PA, Robertson SH, Salzburger M, Seakins PW, Shannon RJ, Shiels OJ, Trevitt AJ, Vallance C, Welz O, Xu X, Zádor J, Zhang RM. The master equation: general discussion. Faraday Discuss 2022; 238:529-574. [DOI: 10.1039/d2fd90050e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Conrad AR, Hansen N, Jasper AW, Thomason NK, Hidaldo-Rodrigues L, Treshock SP, Popolan-Vaida DM. Identification of the acetaldehyde oxide Criegee intermediate reaction network in the ozone-assisted low-temperature oxidation of trans-2-butene. Phys Chem Chem Phys 2021; 23:23554-23566. [PMID: 34651147 DOI: 10.1039/d1cp03126k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Uni- and bi-molecular reactions involving Criegee intermediates (CIs) have been the focus of many studies due to the role these molecules play in atmospheric chemistry. The reactivity of CIs is known to strongly depend on their structure. The reaction network of the second simplest CI, acetaldehyde oxide (CH3CHOO), is investigated in this work in an atmospheric pressure jet-stirred reactor (JSR) during the ozonolysis of trans-2-butene to explore the kinetic pathways relevant to atmospheric chemistry and low-temperature combustion. The mole fraction profiles of reactants, intermediates, and final products are determined by means of molecular-beam mass spectrometry in conjunction with single-photon ionization employing tunable synchrotron-generated vacuum ultraviolet radiation. A network of CI reactions is identified in the temperature region below 600 K, characterized by CI addition to trans-2-butene, water, formaldehyde, formic acid, and methanol. No sequential additions of the CH3CHOO CI are observed, in contrast with the reactivity of the simplest CI (H2COO) and the earlier observation of an extensive reaction network with up to four H2COO sequential additions (Phys. Chem. Chem. Phys., 2019, 21, 7341-7357). Experimental photoionization efficiency scans recorded at 300 K and 425 K and ab initio threshold energy calculations lead to the identification and quantification of previously elusive intermediates, such as ketohydroperoxide and hydroperoxide species. Specifically, the C4H8 + O3 adduct is identified as a ketohydroperoxide (KHP, 3-hydroperoxybutan-2-one, CH3C(O)CH(CH3)OOH), while hydroxyacetaldehyde (glycolaldehyde, HCOCH2OH) formation is attributed to unimolecular isomerization of the CIs. Other hydroperoxide species such as methyl hydroperoxide (CH3OOH), ethyl hydroperoxide (C2H5OOH), butyl hydroperoxide (OOH), hydroperoxyl acetaldehyde (HOOCH2CHO), hydroxyethyl hydroperoxide (CH3CH(OH)OOH), but-1-enyl-3-hydroperoxide, and 4-hydroxy-3-methylpentan-2-one (HOCH(CH3)CH(CH3)C(O)CH3) are also identified. Detection of additional oxygenated species such as methanol, ethanol, ketene, and aldehydes suggests multiple active oxidation routes. These results provide additional evidence that CIs are key intermediates of the ozone-unsaturated hydrocarbon reactions providing critical inputs for improved kinetics models.
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Affiliation(s)
- Alan R Conrad
- Department of Chemistry, University of Central Florida, Orlando, FL 32816, USA.
| | - Nils Hansen
- Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Natasha K Thomason
- Department of Chemistry, University of Central Florida, Orlando, FL 32816, USA.
| | | | - Sean P Treshock
- Department of Chemistry, University of Central Florida, Orlando, FL 32816, USA.
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12
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Moberg DR, Jasper AW, Davis MJ. Parsimonious Potential Energy Surface Expansions Using Dictionary Learning with Multipass Greedy Selection. J Phys Chem Lett 2021; 12:9169-9174. [PMID: 34525799 DOI: 10.1021/acs.jpclett.1c02721] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Potential energy surfaces fit with basis set expansions have been shown to provide accurate representations of electronic energies and have enabled a variety of high-accuracy dynamics, kinetics, and spectroscopy applications. The number of terms in these expansions scales poorly with system size, a drawback that challenges their use for systems with more than ∼10 atoms. A solution is presented here using dictionary learning. Subsets of the full set of conventional basis functions are optimized using a newly developed multipass greedy regression method inspired by forward and backward selection methods from the statistics, signal processing, and machine learning literatures. The optimized representations have accuracies comparable to the full set but are 1 or more orders of magnitude smaller, and notably, the number of terms in the optimized multipass greedy expansions scales approximately linearly with the number of atoms.
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Affiliation(s)
- Daniel R Moberg
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Michael J Davis
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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13
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Abstract
A general strategy is presented for constructing and validating permutationally invariant polynomial (PIP) expansions for chemical systems of any stoichiometry. Demonstrations are made for three categories of gas-phase dynamics and kinetics: collisional energy-transfer trajectories for predicting pressure-dependent kinetics, three-body collisions for describing transient van der Waals adducts relevant to atmospheric chemistry, and nonthermal reactivity via quasiclassical trajectories. In total, 30 systems are considered with up to 15 atoms and 39 degrees of freedom. Permutational invariance is enforced in PIP expansions with as many as 13 million terms and 13 permutationally distinct atom types by taking advantage of petascale computational resources. The quality of the PIP expansions is demonstrated through the systematic convergence of in-sample and out-of-sample errors with respect to both the number of training data and the order of the expansion, and these errors are shown to predict errors in the dynamics for both reactive and nonreactive applications. The parallelized code distributed as part of this work enables the automation of PIP generation for complex systems with multiple channels and flexible user-defined symmetry constraints and for automatically removing unphysical unconnected terms from the basis set expansions, all of which are required for simulating complex reactive systems.
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Affiliation(s)
- Daniel R Moberg
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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14
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Hansen AS, Bhagde T, Moore KB, Moberg DR, Jasper AW, Georgievskii Y, Vansco MF, Klippenstein SJ, Lester MI. Watching a hydroperoxyalkyl radical (•QOOH) dissociate. Science 2021; 373:679-682. [PMID: 34353951 DOI: 10.1126/science.abj0412] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 06/22/2021] [Indexed: 11/02/2022]
Abstract
A prototypical hydroperoxyalkyl radical (•QOOH) intermediate, transiently formed in the oxidation of volatile organic compounds, was directly observed through its infrared fingerprint and energy-dependent unimolecular decay to hydroxyl radical and cyclic ether products. Direct time-domain measurements of •QOOH unimolecular dissociation rates over a wide range of energies were found to be in accord with those predicted theoretically using state-of-the-art electronic structure characterizations of the transition state barrier region. Unimolecular decay was enhanced by substantial heavy-atom tunneling involving O-O elongation and C-C-O angle contraction along the reaction pathway. Master equation modeling yielded a fully a priori prediction of the pressure-dependent thermal unimolecular dissociation rates for the •QOOH intermediate-again increased by heavy-atom tunneling-which are required for global models of atmospheric and combustion chemistry.
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Affiliation(s)
- Anne S Hansen
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Trisha Bhagde
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kevin B Moore
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Daniel R Moberg
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Yuri Georgievskii
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Michael F Vansco
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA.
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA.
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15
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Glarborg P, Hashemi H, Cheskis S, Jasper AW. On the Rate Constant for NH 2+HO 2 and Third-Body Collision Efficiencies for NH 2+H(+M) and NH 2+NH 2(+M). J Phys Chem A 2021; 125:1505-1516. [PMID: 33560846 DOI: 10.1021/acs.jpca.0c11011] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In low-temperature flash photolysis of NH3/O2/N2 mixtures, the NH2 consumption rate and the product distribution is controlled by the reactions NH2 + HO2 → products (R1), NH2 + H (+M) → NH3 (+M) (R2), and NH2 + NH2 (+M) → N2H4 (+M) (R3). In the present work, published flash photolysis experiments by, among others, Cheskis and co-workers, are re-interpreted using recent direct measurements of NH2 + H (+N2) and NH2 + NH2 (+N2) from Altinay and Macdonald. To facilitate analysis of the FP data, relative third-body collision efficiencies compared to N2 for R2 and R3 were calculated for O2 and NH3 as well as for other selected molecules. Results were in good agreement with the limited experimental data. Based on reported NH2 decay rates in flash photolysis of NH3/O2/N2, a rate constant for NH2 + HO2 → NH3 + O2 (R1a) of k1a = 1.5(±0.5) × 1014 cm3 mol-1 s-1 at 295 K was derived. This value is higher than earlier determinations based on the FP results but in good agreement with recent theoretical work. Kinetic modeling of reported N2O yields indicates that NH2 + HO2 → H2NO + O (R1c) is competing with R1a, but perturbation experiments with addition of CH4 indicate that it is not a dominating channel. Measured HNO profiles indicate that this component is formed directly by NH2 + HO2 → HNO + H2O (R1b), but theoretical work indicates that R1b is only a minor channel. Based on this analysis, we estimate k1c = 2.5 × 1013 cm3 mol-1 s-1 and k1b = 2.5 × 1012 cm3 mol-1 s-1 at 295 K, with significant uncertainty margins.
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Affiliation(s)
- Peter Glarborg
- DTU Chemical Engineering, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Hamid Hashemi
- DTU Chemical Engineering, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Sergey Cheskis
- School of Chemistry, Tel Aviv University, Ramat Aviv, IL-69978 Tel Aviv, Israel
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439 United States
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16
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Abstract
The accelerating chemical effect of ozone addition on the oxidation chemistry of methyl hexanoate [CH3(CH2)4C(═O)OCH3] was investigated over a temperature range from 460 to 940 K. Using an externally heated jet-stirred reactor at p = 700 Torr (residence time τ = 1.3 s, stoichiometry φ = 0.5, 80% argon dilution), we explored the relevant chemical pathways by employing molecular-beam mass spectrometry with electron and single-photon ionization to trace the temperature dependencies of key intermediates, including many hydroperoxides. In the absence of ozone, reactivity is observed in the so-called low-temperature chemistry (LTC) regime between 550 and 700 K, which is governed by hydroperoxides formed from sequential O2 addition and isomerization reactions. At temperatures above 700 K, we observed the negative temperature coefficient (NTC) regime, in which the reactivity decreases with increasing temperatures, until near 800 K, where the reactivity increases again. Upon addition of ozone (1000 ppm), the overall reactivity of the system is dramatically changed due to the time scale of ozone decomposition in comparison to fuel oxidation time scales of the mixtures at different temperatures. While the LTC regime seems to be only slightly affected by the addition of ozone with respect to the identity and quantity of the observed intermediates, we observed an increased reactivity in the intermediate NTC temperature range. Furthermore, we observed experimental evidence for an additional oxidation regime in the range near 500 K, herein referred to as the extreme low-temperature chemistry (ELTC) regime. Experimental evidence and theoretical rate constant calculations indicate that this ELTC regime is likely to be initiated by H abstraction from methyl hexanoate via O atoms, which originate from thermal O3 decomposition. The theoretical calculations show that the rate constants for methyl ester initiation via abstraction by O atoms increase dramatically with the size of the methyl ester, suggesting that ELTC is likely not important for the smaller methyl esters. Experimental evidence is provided indicating that, similar to the LTC regime, the chemistry in the ELTC regime is dominated by hydroperoxide chemistry. However, mass spectra recorded at various reactor temperatures and at different photon energies provide experimental evidence of some differences in chemical species between the ELTC and the LTC temperature ranges.
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Affiliation(s)
- Aric C Rousso
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Yiguang Ju
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Nils Hansen
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
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17
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Randazzo JB, Sivaramakrishnan R, Jasper AW, Sikes T, Lynch PT, Tranter RS. An experimental and theoretical study of the high temperature reactions of the four butyl radical isomers. Phys Chem Chem Phys 2020; 22:18304-18319. [PMID: 32785311 DOI: 10.1039/d0cp02404j] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The high temperature gas phase chemistry of the four butyl radical isomers (n-butyl, sec-butyl, iso-butyl, and tert-butyl) was investigated in a combined experimental and theoretical study. Organic nitrites were used as convenient and clean sources of each of the butyl radical isomers. Rate coefficients for dissociation of each nitrite were obtained experimentally and are at, or close to, the high pressure limit. Low pressure experiments were performed in a diaphragmless shock tube with laser schlieren densitometry at post-shock pressures of 65, 130, and 260 Torr and post-shock temperatures of 700-1000 K. Additional experiments were conducted with iso-butyl radicals at 805 K and 8.7 bar to elucidate changes in mechanism at higher pressures. These experiments were performed in a miniature shock tube with synchrotron-based photoionization mass spectrometry. The mass spectra confirmed that scission of the O-NO bond is the primary channel by which the precursors dissociate, but they also provided evidence of a minor channel (<7.7%) through HNO loss and formation of an aldehyde. These high pressure experiments were also used to determine the disproportionation/recombination ratio for iso-butyl radicals as 0.3. Reanalysis of the lower-temperature literature and the present data yielded rate constants for the disproportionation reaction, iso-butyl + iso-butyl = iso-butene + iso-butane. A chemical kinetics model was developed for the reactions of the butyl isomers that included new paths for highly energized adducts. These adducts are formed by the addition of H, CH3 or C2H5 to the butyl radicals. Accompanying theoretical investigations show that chemically activated pathways are competitive with stabilization of the adduct by collision under the conditions of the laser schlieren experiments. These calculations also show that at 10 bar and T < 1000 K stabilization is the only important reaction, but at higher temperatures, even at 10 bar, chemically activated product channels should also be considered. Branching fractions and rate coefficients are presented for these reactions. This study also highlights the importance of the radical structure for determining branching ratios for disproportionation and recombination of alkyl radicals, and these were facilitated by theoretical calculations of recombination rate coefficients for the four butyl radical isomers. The results reveal previously unknown features of butyl radical chemistry under conditions that are relevant to a wide range of applications and reaction mechanisms are presented that incorporate pressure dependent rate coefficients for the key steps.
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Affiliation(s)
- John B Randazzo
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, IL 60439, USA.
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18
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Jasper AW. “Third‐body” collision parameters for hydrocarbons, alcohols, and hydroperoxides and an effective internal rotor approach for estimating them. INT J CHEM KINET 2020. [DOI: 10.1002/kin.21358] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Ahren W. Jasper
- Chemical Sciences and Engineering Division Argonne National Laboratory Lemont Illinois
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19
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Affiliation(s)
- Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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20
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Hansen N, Moshammer K, Jasper AW. Isomer-Selective Detection of Keto-Hydroperoxides in the Low-Temperature Oxidation of Tetrahydrofuran. J Phys Chem A 2019; 123:8274-8284. [PMID: 31483667 DOI: 10.1021/acs.jpca.9b07017] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Keto-hydroperoxides (KHPs) are reactive, partially oxidized intermediates that play a central role in chain-branching reactions during the gas-phase low-temperature oxidation of hydrocarbons and oxygenated species. Although multiple isomeric forms of the KHP intermediate are possible in complex oxidation environments when multiple reactant radicals exist that contain nonequivalent O2 addition sites, isomer-resolved data of KHPs have not been reported. In this work, we provide partially isomer-resolved detection and quantification of the KHPs that form during the low-temperature oxidation of tetrahydrofuran (THF, cycl.-O-CH2CH2CH2CH2-). We describe how these short-lived KHPs were detected, identified, and quantified using integrated experimental and theoretical approaches. The experimental approaches were based on direct molecular-beam sampling from a jet-stirred reactor operated at near-atmospheric pressure and at temperatures between 500 and 700 K, followed by mass spectrometry with single-photon ionization via tunable synchrotron-generated vacuum-ultraviolet radiation, and the identification of fragmentation patterns. The interpretation of the experiments was guided by theoretical calculations of ionization thresholds, fragment appearance energies, and photoionization cross sections. On the basis of the experimentally observed and theoretically calculated ionization and fragment appearance energies, KHP isomers could be distinguished as originating from H-abstraction reactions from either the α-C adjacent to the O atom or the β-C atoms. Temperature-dependent concentration profiles of the partially resolved isomeric KHP intermediates were determined in the range of 500-700 K, and the results indicate that the observed KHP isomers are formed overwhelmingly (∼99%) from the α-C THF radical. Comparisons of the partially isomer-resolved quantification of the KHPs to up-to-date kinetic modeling results reveal new opportunities for the development of a next-generation THF oxidation mechanism.
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Affiliation(s)
- Nils Hansen
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | - Kai Moshammer
- Physikalisch-Technische Bundesanstalt , Bundesallee 100 , 38116 Braunschweig , Germany
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division , Argonne National Laboratory , Lemont , Illinois 60439 , United States
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21
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Jasper AW, Harding LB, Knight C, Georgievskii Y. Anharmonic Rovibrational Partition Functions at High Temperatures: Tests of Reduced-Dimensional Models for Systems with up to Three Fluxional Modes. J Phys Chem A 2019; 123:6210-6228. [DOI: 10.1021/acs.jpca.9b03592] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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22
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Grinberg Dana A, Moore KB, Jasper AW, Green WH. Large Intermediates in Hydrazine Decomposition: A Theoretical Study of the N3H5 and N4H6 Potential Energy Surfaces. J Phys Chem A 2019; 123:4679-4692. [DOI: 10.1021/acs.jpca.9b02217] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alon Grinberg Dana
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Kevin B. Moore
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - William H. Green
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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23
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Jasper AW, Davis MJ. Parameterization Strategies for Intermolecular Potentials for Predicting Trajectory-Based Collision Parameters. J Phys Chem A 2019; 123:3464-3480. [DOI: 10.1021/acs.jpca.9b01918] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Michael J. Davis
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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24
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Abstract
Quasiclassical trajectories are used to compute nonthermal rate constants, k*, for abstraction reactions involving highly-excited methane CH4 * and the radicals H, O, OH, and O2. Several temperatures and internal energies of methane, Evib, are considered, and significant nonthermal rate enhancements for large Evib are found. Specifically, when CH4 * is internally excited close to its dissociation threshold (Evib ≈ D0 = 104 kcal/mol), its reactivity with H, O, and OH is shown to be collision-rate-limited and to approach that of comparably-sized radicals, such as CH3, with k* > 10-10 cm3 molecule-1 s-1. Rate constants this large are more typically associated with barrierless reactions, and at 1000 K, this represents a nonthermal rate enhancement, k*/k, of more than two orders of magnitude relative to thermal rate constants k. We show that large nonthermal rate constants persist even after significant internal cooling, with k*/k > 10 down to Evib ≈ D0/4. The competition between collisional cooling and nonthermal reactivity is studied using a simple model, and nonthermal reactions are shown to account for up to 35%-50% of the fate of the products of H + CH3 = CH4 * under conditions of practical relevance to combustion. Finally, the accuracy of an effective temperature model for estimating k* from k is quantified.
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Affiliation(s)
- Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Raghu Sivaramakrishnan
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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25
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Rousso AC, Hansen N, Jasper AW, Ju Y. Identification of the Criegee intermediate reaction network in ethylene ozonolysis: impact on energy conversion strategies and atmospheric chemistry. Phys Chem Chem Phys 2019; 21:7341-7357. [DOI: 10.1039/c9cp00473d] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction network of the simplest Criegee intermediate (CI) CH2OO has been studied experimentally during the ozonolysis of ethylene.
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Affiliation(s)
- Aric C. Rousso
- Department of Mechanical and Aerospace Engineering
- Princeton University
- USA
| | - Nils Hansen
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - Ahren W. Jasper
- Chemical Sciences and Engineering Division
- Argonne National Laboratory
- Lemont
- USA
| | - Yiguang Ju
- Department of Mechanical and Aerospace Engineering
- Princeton University
- USA
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26
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Abstract
Ethylene oxidation initiated by ozone addition (ozonolysis) is carried out in a jet-stirred reactor from 300 to 1000 K to explore the kinetic pathways relevant to low-temperature oxidation. The temperature dependencies of species' mole fractions are quantified using molecular-beam mass spectrometry with electron ionization and single-photon ionization employing tunable synchrotron-generated vacuum-ultraviolet radiation. Upon ozone addition, significant ethylene oxidation is found in the low-temperature regime from 300 to 600 K. Here, we provide new insights into the ethylene ozonolysis reaction network via identification and quantification of previously elusive intermediates by combining experimental photoionization energy scans and ab initio threshold energy calculations for isomer identification. Specifically, the C2H4 + O3 adduct C2H4O3 is identified as a keto-hydroperoxide (hydroperoxy-acetaldehyde, HOOCH2CHO) based on the calculated and experimentally observed ionization energy of 9.80 (±0.05) eV. Quantification using a photoionization cross-section of 5 Mb at 10.5 eV results in 5 ppm at atmospheric conditions, which decreases monotonically with temperature until 550 K. Other hydroperoxide species that contribute in larger amounts to the low-temperature oxidation of C2H4, like H2O2, CH3OOH, and C2H5OOH, are identified and their temperature-dependent mole fractions are reported. The experimental evidence for additional oxygenated species such as methanol, ketene, acetaldehyde, and hydroxy-acetaldehyde suggest multiple active oxidation routes. This experimental investigation closes the gap between ozonolysis at atmospheric and elevated temperature conditions and provides a database for future modeling.
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Affiliation(s)
- Aric C Rousso
- Department of Mechanical and Aerospace Engineering , Princeton University , Princeton , New Jersey 08544 , United States
| | - Nils Hansen
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Yiguang Ju
- Department of Mechanical and Aerospace Engineering , Princeton University , Princeton , New Jersey 08544 , United States
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27
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Pfeifle M, Ma YT, Jasper AW, Harding LB, Hase WL, Klippenstein SJ. Nascent energy distribution of the Criegee intermediate CH2OO from direct dynamics calculations of primary ozonide dissociation. J Chem Phys 2018; 148:174306. [DOI: 10.1063/1.5028117] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mark Pfeifle
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Yong-Tao Ma
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
| | - Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Lawrence B. Harding
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - William L. Hase
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
| | - Stephen J. Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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28
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Jasper AW, Gruey ZB, Harding LB, Georgievskii Y, Klippenstein SJ, Wagner AF. Anharmonic Rovibrational Partition Functions for Fluxional Species at High Temperatures via Monte Carlo Phase Space Integrals. J Phys Chem A 2018; 122:1727-1740. [DOI: 10.1021/acs.jpca.7b11722] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ahren W. Jasper
- Chemical Sciences and Engineering
Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Zackery B. Gruey
- Chemical Sciences and Engineering
Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Lawrence B. Harding
- Chemical Sciences and Engineering
Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Yuri Georgievskii
- Chemical Sciences and Engineering
Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Stephen J. Klippenstein
- Chemical Sciences and Engineering
Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Albert F. Wagner
- Chemical Sciences and Engineering
Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
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29
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Pfeifle M, Georgievskii Y, Jasper AW, Klippenstein SJ. Theoretical investigation of intersystem crossing in the cyanonitrene molecule, 1NCN → 3NCN. J Chem Phys 2017; 147:084310. [DOI: 10.1063/1.4999788] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mark Pfeifle
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Yuri Georgievskii
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Stephen J. Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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30
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Abstract
Abstract
In this work the kinetics of the TiCl4 ⇌ TiCl3 + Cl reaction is studied theoretically. A variable-reaction coordinate transition-state theory (VRC-TST) is used to calculate the high-pressure limit rate coefficients. The interaction energy surface for the VRC-TST step is sampled directly at the CASPT2(6e,4o)/cc-pVDZ level of theory including an approximate treatment of the spin-orbit coupling. The pressure-dependence of the reaction in an argon bath gas is explored using the master equation in conjunction with the optimised VRC-TST transition-state number of states. The collisional energy transfer parameters for the TiCl4–Ar system are estimated via a “one-dimensional minimisation” method and classical trajectories. The Ti–Cl bond dissociation energy is computed using a complete basis set extrapolation technique with cc-pVQZ and cc-pV5Z basis sets. Good quantitative agreement between the estimated rate constants and available literature data is observed. However, the fall-off behaviour of the model results is not seen in the current experimental data. Sensitivity analysis shows that the fall-off effect is insensitive to the choice of model parameters and methods. More experimental work and development of higher-level theoretical methods are needed to further investigate this discrepancy.
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Affiliation(s)
- Daniel Nurkowski
- Department of Chemical Engineering and Biotechnology University of Cambridge New Museums Site , Pembroke Street, CB2 3RA , Cambridge , UK
| | - Ahren W. Jasper
- Sandia National Laboratories, Combustion Research Facility , Livermore , CA 94551-0969, USA
| | - Jethro Akroyd
- Department of Chemical Engineering and Biotechnology University of Cambridge New Museums Site , Pembroke Street, CB2 3RA , Cambridge , UK
| | - Markus Kraft
- Department of Chemical Engineering and Biotechnology University of Cambridge New Museums Site , Pembroke Street, CB2 3RA , Cambridge , UK
- School of Chemical and Biomedical Engineering Nanyang Technological University , 62 Nanyang Drive , Singapore 637459
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31
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Moshammer K, Jasper AW, Popolan-Vaida DM, Wang Z, Bhavani Shankar VS, Ruwe L, Taatjes CA, Dagaut P, Hansen N. Quantification of the Keto-Hydroperoxide (HOOCH2OCHO) and Other Elusive Intermediates during Low-Temperature Oxidation of Dimethyl Ether. J Phys Chem A 2016; 120:7890-7901. [DOI: 10.1021/acs.jpca.6b06634] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kai Moshammer
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Ahren W. Jasper
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Denisia M. Popolan-Vaida
- Department
of
Chemistry, University of California—Berkeley, and Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Zhandong Wang
- King
Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (CCRC), Thuwal 23955-6900, Saudi Arabia
| | - Vijai Shankar Bhavani Shankar
- King
Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (CCRC), Thuwal 23955-6900, Saudi Arabia
| | - Lena Ruwe
- Department
of Chemistry, Bielefeld University, D-33615 Bielefeld, Germany
| | - Craig A. Taatjes
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Philippe Dagaut
- Centre National
de la Recherche Scientifique (CNRS-INSIS), ICARE, 45071 Orléans Cedex 2, France
| | - Nils Hansen
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
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32
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Nangia S, Jasper AW, Miller TF, Truhlar DG. Erratum: “Army ants algorithm for rare event sampling of delocalized nonadiabatic transitions by trajectory surface hopping and the estimation of sampling errors by the bootstrap method” [J. Chem. Phys. 120, 3586 (2004)]. J Chem Phys 2016; 144:139901. [DOI: 10.1063/1.4944694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Shikha Nangia
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA
| | - Ahren W. Jasper
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA
| | - Thomas F. Miller
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA
| | - Donald G. Truhlar
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA
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33
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Bourgalais J, Roussel V, Capron M, Benidar A, Jasper AW, Klippenstein SJ, Biennier L, Le Picard SD. Low Temperature Kinetics of the First Steps of Water Cluster Formation. Phys Rev Lett 2016; 116:113401. [PMID: 27035301 DOI: 10.1103/physrevlett.116.113401] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 06/05/2023]
Abstract
We present a combined experimental and theoretical low temperature kinetic study of water cluster formation. Water cluster growth takes place in low temperature (23-69 K) supersonic flows. The observed kinetics of formation of water clusters are reproduced with a kinetic model based on theoretical predictions for the first steps of clusterization. The temperature- and pressure-dependent association and dissociation rate coefficients are predicted with an ab initio transition state theory based master equation approach over a wide range of temperatures (20-100 K) and pressures (10^{-6}-10 bar).
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Affiliation(s)
- J Bourgalais
- Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 263 avenue Général Leclerc, 35042 Rennes cedex, France
| | - V Roussel
- Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 263 avenue Général Leclerc, 35042 Rennes cedex, France
| | - M Capron
- Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 263 avenue Général Leclerc, 35042 Rennes cedex, France
| | - A Benidar
- Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 263 avenue Général Leclerc, 35042 Rennes cedex, France
| | - A W Jasper
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA
| | - S J Klippenstein
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - L Biennier
- Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 263 avenue Général Leclerc, 35042 Rennes cedex, France
| | - S D Le Picard
- Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 263 avenue Général Leclerc, 35042 Rennes cedex, France
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34
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Miller JA, Klippenstein SJ, Robertson SH, Pilling MJ, Shannon R, Zádor J, Jasper AW, Goldsmith CF, Burke MP. Comment on “When Rate Constants Are Not Enough”. J Phys Chem A 2016; 120:306-12. [DOI: 10.1021/acs.jpca.5b06025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- James A. Miller
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Stephen J. Klippenstein
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | | | | | - Robin Shannon
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | - Judit Zádor
- Combustion
Research Facility, MS 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Ahren W. Jasper
- Combustion
Research Facility, MS 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - C. Franklin Goldsmith
- School
of Engineering, Brown University, Providence, Rhode Island 02912, United States
| | - Michael P. Burke
- Department
of Mechanical Engineering, Department of Chemical Engineering, and
Data Sciences Institute, Columbia University, New York, New York 10027, United States
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35
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Mebel AM, Georgievskii Y, Jasper AW, Klippenstein SJ. Pressure-dependent rate constants for PAH growth: formation of indene and its conversion to naphthalene. Faraday Discuss 2016; 195:637-670. [DOI: 10.1039/c6fd00111d] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unraveling the mechanisms for growth of polycyclic aromatic hydrocarbons (PAHs) requires accurate temperature- and pressure-dependent rate coefficients for a great variety of feasible pathways. Even the pathways for the formation of the simplest PAHs, indene and naphthalene, are fairly complex. These pathways provide important prototypes for modeling larger PAH growth. In this work we employ the ab initio RRKM theory-based master equation approach to predict the rate constants involved in the formation of indene and its conversion to naphthalene. The reactions eventually leading to indene involve C9Hx (x = 8–11) potential energy surfaces (PESs) and include C6H5 + C3H4 (allene and propyne), C6H6 + C3H3, benzyl + C2H2, C6H5 + C3H6, C6H6 + C3H5 and C6H5 + C3H5. These predictions allow us to make a number of valuable observations on the role of various mechanisms. For instance, we demonstrate that reactions which can significantly contribute to the formation of indene include phenyl + allene and H-assisted isomerization to indene of its major product, 3-phenylpropyne, benzyl + acetylene, and the reactions of the phenyl radical with propene and the allyl radical, both proceeding via the 3-phenylpropene intermediate. 3-Phenylpropene can be activated to a 1-phenylallyl radical, which in turn rapidly decomposes to indene. Next, indene can be converted to benzofulvene or naphthalene under typical combustion conditions, via its activation by H atom abstraction and methyl substitution on the five-membered ring followed by isomerization and decomposition of the resulting 1-methylindenyl radical, C10H9 → C10H8 + H. Alternatively, the same region of the C10H9 PES can be accessed through the reaction of benzyl with propargyl, C7H7 + C3H3 → C10H10 → C10H9 + H, which therefore can also contribute to the formation of benzofulvene or naphthalene. Benzofulvene easily transforms to naphthalene by H-assisted isomerization. An analysis of the effect of pressure on the reaction outcome and relative product yields is given, and modified Arrhenius fits of the rate constants are reported for the majority of the considered reactions. Ultimately, the implementation of such expressions in detailed kinetic models will help quantify the role of these reactions for PAH growth in various environments.
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Affiliation(s)
- Alexander M. Mebel
- Department of Chemistry and Biochemistry
- Florida International University
- Miami
- USA
| | - Yuri Georgievskii
- Chemical Sciences and Engineering Division
- Argonne National Laboratory
- Argonne
- USA
| | - Ahren W. Jasper
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
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36
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Steill JD, Jasper AW, Chandler DW. Determination of the collisional energy transfer distribution responsible for the collision-induced dissociation of NO2 with Ar. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.06.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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37
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Abstract
Due to the prominent role of the propargyl radical for hydrocarbon growth within combustion environments, it is important to understand the kinetics of its formation and loss. The ab initio transition state theory-based master equation method is used to obtain theoretical kinetic predictions for the temperature and pressure dependence of the thermal decomposition of propargyl, which may be its primary loss channel under some conditions. The potential energy surface for the decomposition of propargyl is first mapped at a high level of theory with a combination of coupled cluster and multireference perturbation calculations. Variational transition state theory is then used to predict the microcanonical rate coefficients, which are subsequently implemented within the multiple-well multiple-channel master equation. A variety of energy transfer parameters are considered, and the sensitivity of the thermal rate predictions to these parameters is explored. The predictions for the thermal decomposition rate coefficient are found to be in good agreement with the limited experimental data. Modified Arrhenius representations of the rate constants are reported for utility in combustion modeling.
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Affiliation(s)
- Stephen J Klippenstein
- †Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - James A Miller
- †Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Ahren W Jasper
- ‡Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
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38
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Jasper AW. Multidimensional Effects in Nonadiabatic Statistical Theories of Spin-Forbidden Kinetics: A Case Study of 3O + CO → CO2. J Phys Chem A 2015; 119:7339-51. [DOI: 10.1021/jp512942w] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ahren W. Jasper
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
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39
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Annesley CJ, Randazzo JB, Klippenstein SJ, Harding LB, Jasper AW, Georgievskii Y, Ruscic B, Tranter RS. Thermal Dissociation and Roaming Isomerization of Nitromethane: Experiment and Theory. J Phys Chem A 2015; 119:7872-93. [DOI: 10.1021/acs.jpca.5b01563] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher J. Annesley
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - John B. Randazzo
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Stephen J. Klippenstein
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Lawrence B. Harding
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Ahren W. Jasper
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Yuri Georgievskii
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Branko Ruscic
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Robert S. Tranter
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
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40
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Moshammer K, Jasper AW, Popolan-Vaida DM, Lucassen A, Diévart P, Selim H, Eskola AJ, Taatjes CA, Leone SR, Sarathy SM, Ju Y, Dagaut P, Kohse-Höinghaus K, Hansen N. Detection and Identification of the Keto-Hydroperoxide (HOOCH2OCHO) and Other Intermediates during Low-Temperature Oxidation of Dimethyl Ether. J Phys Chem A 2015; 119:7361-74. [PMID: 25695304 DOI: 10.1021/acs.jpca.5b00101] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this paper we report the detection and identification of the keto-hydroperoxide (hydroperoxymethyl formate, HPMF, HOOCH2OCHO) and other partially oxidized intermediate species arising from the low-temperature (540 K) oxidation of dimethyl ether (DME). These observations were made possible by coupling a jet-stirred reactor with molecular-beam sampling capabilities, operated near atmospheric pressure, to a reflectron time-of-flight mass spectrometer that employs single-photon ionization via tunable synchrotron-generated vacuum-ultraviolet radiation. On the basis of experimentally observed ionization thresholds and fragmentation appearance energies, interpreted with the aid of ab initio calculations, we have identified HPMF and its conceivable decomposition products HC(O)O(O)CH (formic acid anhydride), HC(O)OOH (performic acid), and HOC(O)OH (carbonic acid). Other intermediates that were detected and identified include HC(O)OCH3 (methyl formate), cycl-CH2-O-CH2-O- (1,3-dioxetane), CH3OOH (methyl hydroperoxide), HC(O)OH (formic acid), and H2O2 (hydrogen peroxide). We show that the theoretical characterization of multiple conformeric structures of some intermediates is required when interpreting the experimentally observed ionization thresholds, and a simple method is presented for estimating the importance of multiple conformers at the estimated temperature (∼100 K) of the present molecular beam. We also discuss possible formation pathways of the detected species: for example, supported by potential energy surface calculations, we show that performic acid may be a minor channel of the O2 + ĊH2OCH2OOH reaction, resulting from the decomposition of the HOOCH2OĊHOOH intermediate, which predominantly leads to the HPMF.
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Affiliation(s)
- Kai Moshammer
- †Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States.,‡Department of Chemistry, Bielefeld University, D-33615 Bielefeld, Germany
| | - Ahren W Jasper
- †Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Denisia M Popolan-Vaida
- §Departments of Chemistry and Physics, University of California, Berkeley, California 94720, United States.,∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Arnas Lucassen
- †Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Pascal Diévart
- ⊥Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Hatem Selim
- #Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Arkke J Eskola
- †Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Craig A Taatjes
- †Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Stephen R Leone
- §Departments of Chemistry and Physics, University of California, Berkeley, California 94720, United States.,∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - S Mani Sarathy
- #Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Yiguang Ju
- ⊥Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Philippe Dagaut
- ∇Centre National de la Recherche Scientifique (CNRS), INSIS, 45071 Orléans Cedex 2, France
| | | | - Nils Hansen
- †Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
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41
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Nurkowski D, Klippenstein SJ, Georgievskii Y, Verdicchio M, Jasper AW, Akroyd J, Mosbach S, Kraft M. Ab initio Variational Transition State Theory and Master Equation Study of the Reaction (OH)3SiOCH2 + CH3 ⇌ (OH)3SiOC2H5. Z PHYS CHEM 2015. [DOI: 10.1515/zpch-2014-0640] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In this paper we use variable reaction coordinate variational
transition state theory (VRC-TST) to calculate the reaction
rate constants for the two reactions, R1:
(OH)3SiOCH2 + CH3 ⇌ (OH)3SiOC2H5,
and R2:
CH2OH + CH3 ⇌ C2H5OH. The
first reaction is an important channel during the thermal
decomposition of tetraethoxysilane (TEOS), and its rate
coefficient is the main focus of this work. The second
reaction is analogous to the first and is used as a basis for
comparison. The interaction energies are obtained on-the-fly
at the CASPT2(2e,2o)/cc-pVDZ level of
theory. A one-dimensional correction to the sampled energies
was introduced to account for the energetic effects of
geometry relaxation along the reaction path. The computed,
high-pressure rate coefficients were calculated to be, R1:
k
1 = 2.406 × 10−10
T
−0.301 exp (− 271.4/T) cm3 molecule
–1 s
–1
and R2:
k
2 = 1.316 × 10−10
T
−0.189 exp (− 256.5/T) cm3 molecule
–1 s
–1. These
rates differ from each other by only 10% – 30%
over the temperature range
300–2000 K. A comparison of the computed rates
with experimental data shows good agreement and an improvement
over previous results. The pressure dependency of the reaction
R1 is explored by solving a master equation using helium as
a bath gas. The results obtained show that the reaction is
only weakly pressure dependent over the temperature range
300–1700 K, with the predicted rate constant
being within 50% of its high-pressure limit at
atmospheric pressure.
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Affiliation(s)
- Daniel Nurkowski
- Department of Chemical Engineering and Biotechnology, University of Cambridge New Museums Site, Pembroke Street, CB2 3RA, Cambridge, UK
| | | | - Yuri Georgievskii
- Chemical Sciences and Engineering Division, Argonne National Laboratory, IL 60439, US
| | - Marco Verdicchio
- Chemical Sciences and Engineering Division, Argonne National Laboratory, IL 60439, US
| | - Ahren W. Jasper
- Sandia National Laboratories, Combustion Research Facility, Livermore, CA 94551-0969, US
| | - Jethro Akroyd
- Department of Chemical Engineering and Biotechnology, University of Cambridge New Museums Site, Pembroke Street, CB2 3RA, Cambridge, UK
| | - Sebastian Mosbach
- Department of Chemical Engineering and Biotechnology, University of Cambridge New Museums Site, Pembroke Street, CB2 3RA, Cambridge, UK
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42
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Abstract
The ability to predict the pressure dependence of chemical reaction rates would be a great boon to kinetic modeling of processes such as combustion and atmospheric chemistry. This pressure dependence is intimately related to the rate of collision-induced transitions in energy E and angular momentum J. We present a scheme for predicting this pressure dependence based on coupling trajectory-based determinations of moments of the E,J-resolved collisional transfer rates with the two-dimensional master equation. This completely a priori procedure provides a means for proceeding beyond the empiricism of prior work. The requisite microcanonical dissociation rates are obtained from ab initio transition state theory. Predictions for the CH4 = CH3 + H and C2H3 = C2H2 + H reaction systems are in excellent agreement with experiment.
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43
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Jasper AW, Kamarchik E, Miller JA, Klippenstein SJ. First-principles binary diffusion coefficients for H, H2, and four normal alkanes + N2. J Chem Phys 2014; 141:124313. [DOI: 10.1063/1.4896368] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ahren W. Jasper
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA
| | - Eugene Kamarchik
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA
| | - James A. Miller
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Stephen J. Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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44
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Jasper AW, Miller JA, Klippenstein SJ. Collision Efficiency of Water in the Unimolecular Reaction CH4 (+H2O) ⇆ CH3 + H (+H2O): One-Dimensional and Two-Dimensional Solutions of the Low-Pressure-Limit Master Equation. J Phys Chem A 2013; 117:12243-55. [DOI: 10.1021/jp409086w] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ahren W. Jasper
- Combustion
Research Facility, Sandia National Laboratories, P.O. Box 969, Livermore, California 94551-0969, United States
| | - James A. Miller
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Stephen J. Klippenstein
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
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45
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Jasper AW, Dawes R. Non-Born–Oppenheimer molecular dynamics of the spin-forbidden reaction O(3P) + CO(X 1Σ+) → CO2(X̃Σg+1). J Chem Phys 2013; 139:154313. [DOI: 10.1063/1.4825204] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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46
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Kamarchik E, Jasper AW. Anharmonic state counts and partition functions for molecules via classical phase space integrals in curvilinear coordinates. J Chem Phys 2013; 138:194109. [DOI: 10.1063/1.4804420] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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Abstract
Recent studies have questioned the separability of the tight and roaming mechanisms to molecular decomposition. We explore this issue for a variety of reactions including MgH(2) → Mg + H(2), NCN → CNN, H(2)CO → H(2) + CO, CH(3)CHO → CH(4) + CO, and HNNOH → N(2) + H(2)O. Our analysis focuses on the role of second-order saddle points in defining global dividing surfaces that encompass both tight and roaming first-order saddle points. The second-order saddle points define an energetic criterion for separability of the two mechanisms. Furthermore, plots of the differential contribution to the reactive flux along paths connecting the first- and second-order saddle points provide a dynamic criterion for separability. The minimum in the differential reactive flux in the neighborhood of the second-order saddle point plays the role of a mechanism divider, with the presence of a strong minimum indicating that the roaming and tight mechanisms are dynamically distinct. We show that the mechanism divider is often, but not always, associated with a second-order saddle point. For the formaldehyde and acetaldehyde reactions, we find that the minimum energy geometry on a conical intersection is associated with the mechanism divider for the tight and roaming processes. For HNNOH, we again find that the roaming and tight processes are dynamically separable but we find no intrinsic feature of the potential energy surface associated with the mechanism divider. Overall, our calculations suggest that roaming and tight mechanisms are generally separable over broad ranges of energy covering most kinetically relevant regimes.
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Affiliation(s)
- Lawrence B Harding
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
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48
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Kasper T, Lucassen A, Jasper AW, Li W, Westmoreland PR, Kohse-Höinghaus K, Yang B, Wang J, Cool TA, Hansen N. Identification of Tetrahydrofuran Reaction Pathways in Premixed Flames. ACTA ACUST UNITED AC 2011. [DOI: 10.1524/zpch.2011.0163] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Premixed low-pressure tetrahydrofuran/oxygen/argon flames are investigated by photoionization molecular-beam mass spectrometry using vacuum-ultraviolet synchrotron radiation. For two equivalence ratios (φ = 1.00 and 1.75), mole fractions are measured as a function of distance from the burner for almost 60 intermediates with molar masses ranging from 2 (H2) to 88 (C4H6O2), providing a broad database for flame modeling studies. The isomeric composition is resolved by comparisons between experimental photoionization efficiency data and theoretical simulations, based on calculated ionization energies and Franck-Condon factors. Special emphasis is put on the resolution of the first reaction steps in the fuel destruction. The photoionization experiments are complemented by electron-ionization molecular-beam mass-spectrometry measurements that provide data with high mass resolution. For three additional flames with intermediate equivalence ratios (φ = 1.20, 1.40 and 1.60), mole fractions of major species and photoionization efficiency spectra of intermediate species are reported, extending the database for the development of chemical kinetic models.
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Affiliation(s)
| | - Arnas Lucassen
- Bielefeld University, Department of Chemistry, Bielefeld, Deutschland
| | - Ahren W. Jasper
- Sandia National Laboratories, Combustion Research Facility, Livermore, CA 94551, U.S.A
| | - Wenjun Li
- North Carolina State University, Department of Chemical and Biomolecular Engineerin, Raleigh, NC 27695, U.S.A
| | - Philip R. Westmoreland
- North Carolina State University, Department of Chemical and Biomolecular Engineerin, Raleigh, NC 27695, U.S.A
| | | | - Bin Yang
- Cornell University, School of Applied Engineering Physics, Ithaca, NY 14853, U.S.A
| | - Juan Wang
- Cornell University, School of Applied Engineering Physics, Ithaca, NY 14853, U.S.A
| | - Terrill A. Cool
- Cornell University, School of Applied Engineering Physics, Ithaca, NY 14853, U.S.A
| | - Nils Hansen
- Sandia National Laboratories, Combustion Research Facility, Livermore, CA 94551, U.S.A
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49
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Jasper AW, Truhlar DG. Non-Born—Oppenheimer Molecular Dynamics for Conical Intersections, Avoided Crossings, and Weak Interactions. Advanced Series in Physical Chemistry 2011. [DOI: 10.1142/9789814313452_0010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ahren W. Jasper
- Combustion Research Facility, Sandia National Laboratories, PO Box 969, Livermore, CA 94551-0969, USA
| | - Donald G. Truhlar
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, MN 55455-0431, USA
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50
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Jasper AW, Miller JA. Theoretical Unimolecular Kinetics for CH4 + M ⇄ CH3 + H + M in Eight Baths, M = He, Ne, Ar, Kr, H2, N2, CO, and CH4. J Phys Chem A 2011; 115:6438-55. [DOI: 10.1021/jp200048n] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Ahren W. Jasper
- Combustion Research Facility, Sandia National Laboratories, P.O. Box 969, Livermore, California 94551-0969, United States
| | - James A. Miller
- Combustion Research Facility, Sandia National Laboratories, P.O. Box 969, Livermore, California 94551-0969, United States
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