1
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Zhang J, Zhang H, Qin Z, Kang Y, Hong X, Hou T. Quasiclassical Trajectory Simulation as a Protocol to Build Locally Accurate Machine Learning Potentials. J Chem Inf Model 2023; 63:1133-1142. [PMID: 36791039 DOI: 10.1021/acs.jcim.2c01497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Direct trajectory calculations have become increasingly popular in recent computational chemistry investigations. However, the exorbitant computational cost of ab initio trajectory calculations usually limits its application in mechanistic explorations. Recently, machine learning-based potential energy surface (ML-PES) provides a powerful strategy to circumvent the heavy computational cost and meanwhile maintain the required accuracy. Despite the appealing potential, constructing a robust ML-PES is still challenging since the training set of the PES should cover a broad enough configuration space. In this work, we demonstrate that when the concerned properties could be collected by the localized sampling of the configuration space, quasiclassical trajectory (QCT) calculations can be invoked to efficiently obtain locally accurate ML-PESs. We prove our concept with two model reactions: methyl migration of i-pentane cation and dimerization of cyclopentadiene. We found that the locally accurate ML-PESs are sufficiently robust for reproducing the static and dynamic features of the reactions, including the time-resolved free energy and entropy changes, and time gaps.
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Affiliation(s)
- Jintu Zhang
- Innovation Institute for Artificial Intelligence in Medicine of Zhejiang University, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Haotian Zhang
- Innovation Institute for Artificial Intelligence in Medicine of Zhejiang University, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Zhixin Qin
- Center of Chemistry for Frontier Technologies, Department of Chemistry, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Yu Kang
- Innovation Institute for Artificial Intelligence in Medicine of Zhejiang University, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Xin Hong
- Center of Chemistry for Frontier Technologies, Department of Chemistry, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, Zhejiang, China.,Beijing National Laboratory for Molecular Sciences, North First Street No. 2, Zhongguancun, Beijing 100190, China.,Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang, China
| | - Tingjun Hou
- Innovation Institute for Artificial Intelligence in Medicine of Zhejiang University, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.,State Key Laboratory of Computer-aided Design & Computer Graphics, Zhejiang University, Hangzhou 310058, Zhejiang, China
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2
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Espinosa-Garcia J, Corchado JC. Theoretical study of the Cl( 2P) + SiH 4 reaction: global potential energy surface and product pair-correlated distributions. Comparison with experiment. Phys Chem Chem Phys 2021; 23:21065-21077. [PMID: 34523628 DOI: 10.1039/d1cp02563e] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For the theoretical study of the title reaction, an analytical full-dimensional potential energy surface named PES-2021 was developed for the first time, by fitting high-level explicitly-correlated ab initio data. This reaction presented high exothermicity, (298 K) = -11.6 kcal mol-1, reproducing the experimental evidence; it is a barrierless reaction and no intermediate complexes were found. PES-2021 is a continuous and smooth potential energy surface, it includes intuitive concepts in its development and fitting, such as stretching and bending nuclear motions, and it presents analytical first energy derivatives. Based on PES-2021, kinetics and dynamics studies were carried out using quasi-classical trajectory calculations. In the kinetics study, over the temperature range 300-450 K, we observed that rate constants were practically independent of temperature, with an almost zero activation energy, as compared to 0.0 and -0.48 kcal mol-1 experimentally reported. In this kinetics study the role of the spin-orbit effect on reactivity was analysed. In the dynamics study, different product pair-correlated dynamics properties were compared with the only experimental evidence: product energy partition, product vibrational distribution, product angular distribution and product speed distribution. We observed two mechanisms of reaction, a stripping mechanism associated with large impact parameters and forward scattering, and an indirect mechanism associated with sideways-backward scattering related with "nearly-trapped" trajectories due to the product rotation. In general, theoretical results reasonably simulate the experimental measurements when they consider some rotational and vibrational constraints as well as binning techniques to mimic a quantum-mechanical behaviour. Although the agreement is not quantitative, the present results shed light on the mechanism of this difficult polyatomic reactive system.
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Affiliation(s)
- J Espinosa-Garcia
- Área de Química Física and Instituto de Computación Científica Avanzada, Universidad de Extremadura, 06071 Badajoz, Spain.
| | - J C Corchado
- Área de Química Física and Instituto de Computación Científica Avanzada, Universidad de Extremadura, 06071 Badajoz, Spain.
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3
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Quasi-Classical Trajectory Study of the CN + NH 3 Reaction Based on a Global Potential Energy Surface. Molecules 2021; 26:molecules26040994. [PMID: 33668582 PMCID: PMC7918900 DOI: 10.3390/molecules26040994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/10/2021] [Accepted: 02/11/2021] [Indexed: 11/17/2022] Open
Abstract
Based on a combination of valence-bond and molecular mechanics functions which were fitted to high-level ab initio calculations, we constructed an analytical full-dimensional potential energy surface, named PES-2020, for the hydrogen abstraction title reaction for the first time. This surface is symmetrical with respect to the permutation of the three hydrogens in ammonia, it presents numerical gradients and it improves the description presented by previous theoretical studies. In order to analyze its quality and accuracy, stringent tests were performed, exhaustive kinetics and dynamics studies were carried out using quasi-classical trajectory calculations, and the results were compared with the available experimental evidence. Firstly, the properties (geometry, vibrational frequency and energy) of all stationary points were found to reasonably reproduce the ab initio information used as input; due to the complicated topology with deep wells in the entrance and exit channels and a “submerged” transition state, the description of the intermediate complexes was poorer, although it was adequate to reasonably simulate the kinetics and dynamics of the title reaction. Secondly, in the kinetics study, the rate constants simulated the experimental data in the wide temperature range of 25–700 K, improving the description presented by previous theoretical studies. In addition, while previous studies failed in the description of the kinetic isotope effects, our results reproduced the experimental information. Finally, in the dynamics study, we analyzed the role of the vibrational and rotational excitation of the CN(v,j) reactant and product angular scattering distribution. We found that vibrational excitation by one quantum slightly increased reactivity, thus reproducing the only experimental measurement, while rotational excitation strongly decreased reactivity. The scattering distribution presented a forward-backward shape, associated with the presence of deep wells along the reaction path. These last two findings await experimental confirmation.
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4
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Jonusas M, Leroux K, Krim L. N + H surface reaction under interstellar conditions: Does the NH/NH2/NH3 distribution depend on N/H ratio? J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128736] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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5
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Elishav O, Mosevitzky Lis B, Miller EM, Arent DJ, Valera-Medina A, Grinberg Dana A, Shter GE, Grader GS. Progress and Prospective of Nitrogen-Based Alternative Fuels. Chem Rev 2020; 120:5352-5436. [PMID: 32501681 DOI: 10.1021/acs.chemrev.9b00538] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Alternative fuels are essential to enable the transition to a sustainable and environmentally friendly energy supply. Synthetic fuels derived from renewable energies can act as energy storage media, thus mitigating the effects of fossil fuels on environment and health. Their economic viability, environmental impact, and compatibility with current infrastructure and technologies are fuel and power source specific. Nitrogen-based fuels pose one possible synthetic fuel pathway. In this review, we discuss the progress and current research on utilization of nitrogen-based fuels in power applications, covering the complete fuel cycle. We cover the production, distribution, and storage of nitrogen-based fuels. We assess much of the existing literature on the reactions involved in the ammonia to nitrogen atom pathway in nitrogen-based fuel combustion. Furthermore, we discuss nitrogen-based fuel applications ranging from combustion engines to gas turbines, as well as their exploitation by suggested end-uses. Thereby, we evaluate the potential opportunities and challenges of expanding the role of nitrogen-based molecules in the energy sector, outlining their use as energy carriers in relevant fields.
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Affiliation(s)
- Oren Elishav
- The Nancy and Stephen Grand Technion Energy Program, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Bar Mosevitzky Lis
- The Wolfson Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Elisa M Miller
- Materials and Chemical Science and Technology Directorate, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Douglas J Arent
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Agustin Valera-Medina
- College of Physical Sciences and Engineering, Cardiff University, Wales, United Kingdom
| | - Alon Grinberg Dana
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Gennady E Shter
- The Wolfson Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Gideon S Grader
- The Nancy and Stephen Grand Technion Energy Program, Technion - Israel Institute of Technology, Haifa 3200003, Israel.,The Wolfson Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
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6
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Zhang Z, Gatti F, Zhang DH. Full dimensional quantum mechanical calculations of the reaction probability of the H + NH3 collision based on a mixed Jacobi and Radau description. J Chem Phys 2019; 150:204301. [DOI: 10.1063/1.5096047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Zhaojun Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
| | - Fabien Gatti
- ISMO, Institut des Sciences Moléculaires d’Orsay—UMR 8214 CNRS/Université Paris-Sud, F-91405 Orsay, France
| | - Dong H. Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
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7
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Nguyen TL, Stanton JF. Ab initio thermal rate coefficients for H + NH3⇌ H2+ NH2. INT J CHEM KINET 2019. [DOI: 10.1002/kin.21255] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Thanh Lam Nguyen
- Quantum Theory ProjectDepartments of Chemistry and PhysicsUniversity of Florida Gainesville Florida
| | - John F. Stanton
- Quantum Theory ProjectDepartments of Chemistry and PhysicsUniversity of Florida Gainesville Florida
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8
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Euclides HO, P Barreto PR. APUAMA: a software tool for reaction rate calculations. J Mol Model 2017; 23:176. [PMID: 28477240 DOI: 10.1007/s00894-017-3337-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 03/27/2017] [Indexed: 10/19/2022]
Abstract
APUAMA is a free software designed to determine the reaction rate and thermodynamic properties of chemical species of a reagent system. With data from electronic structure calculations, the APUAMA determine the rate constant with tunneling correction, such as Wigner, Eckart and small curvature, and also, include the rovibrational level of diatomic molecules. The results are presented in the form of Arrhenius-Kooij form, for the reaction rate, and the thermodynamic properties are written down in the polynomial form. The word APUAMA means "fast" in Tupi-Guarani Brazilian language, then the code calculates the reaction rate on a simple and intuitive graphic interface, the form fast and practical. As program output, there are several ASCII files with tabulated information for rate constant, rovibrational levels, energy barriers and enthalpy of reaction, Arrhenius-Kooij coefficient, and also, the option to the User save all graphics in BMP format.
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Affiliation(s)
- Henrique O Euclides
- Laboratório Associado de Plasma-LAP, Instituto Nacional de Pesquisas Espaciais-INPE/MCT, CP515, São José dos Campos, SP, CEP 12247-970, Brazil
| | - Patricia R P Barreto
- Laboratório Associado de Plasma-LAP, Instituto Nacional de Pesquisas Espaciais-INPE/MCT, CP515, São José dos Campos, SP, CEP 12247-970, Brazil.
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9
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Fu B, Shan X, Zhang DH, Clary DC. Recent advances in quantum scattering calculations on polyatomic bimolecular reactions. Chem Soc Rev 2017; 46:7625-7649. [DOI: 10.1039/c7cs00526a] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review surveys quantum scattering calculations on chemical reactions of polyatomic molecules in the gas phase published in the last ten years.
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Affiliation(s)
- Bina Fu
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian 116023
- China
| | - Xiao Shan
- Physical and Theoretical Chemistry Laboratory
- Department of Chemistry
- University of Oxford
- Oxford
- UK
| | - Dong H. Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian 116023
- China
| | - David C. Clary
- Physical and Theoretical Chemistry Laboratory
- Department of Chemistry
- University of Oxford
- Oxford
- UK
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10
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Song H, Yang M, Guo H. Communication: Equivalence between symmetric and antisymmetric stretching modes of NH3 in promoting H + NH3 → H2 + NH2 reaction. J Chem Phys 2016; 145:131101. [DOI: 10.1063/1.4963286] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Hongwei Song
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Minghui Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
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11
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Hu Q, Song H, Johnson CJ, Li J, Guo H, Continetti RE. Imaging a multidimensional multichannel potential energy surface: Photodetachment of H−(NH3) and NH4−. J Chem Phys 2016; 144:244311. [DOI: 10.1063/1.4954187] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Qichi Hu
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, USA
| | - Hongwei Song
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Christopher J. Johnson
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, USA
| | - Jun Li
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Robert E. Continetti
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, USA
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12
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13
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Zavitsas AA. Insights Gained by Modeling the Kinetics of Archetypal Hydrogen Atom Transfer Reactions: NH3
+ ·H ⇆ H2
N· + H2
and CH4
+ ·H ⇆ H3
C· + H2. INT J CHEM KINET 2015. [DOI: 10.1002/kin.20937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Andreas A. Zavitsas
- Department of Chemistry and Biochemistry; Long Island University; University Plaza; Brooklyn NY 11201
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14
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Ravasio S, Momose T, Fujii K, Shimogaki Y, Sugiyama M, Cavallotti C. Analysis of the Gas Phase Kinetics Active during GaN Deposition from NH3 and Ga(CH3)3. J Phys Chem A 2015; 119:7858-71. [PMID: 25919948 DOI: 10.1021/acs.jpca.5b01425] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The results of a systematic investigation aimed at determining the dominant gas phase chemistry active during GaN MOVPE are reported and discussed in this work. This study was performed developing a thermodynamic database including the most stable GaN gas phase species and a gas phase mechanism that could efficiently describe their interconversion kinetics. The thermodynamic data and the kinetic mechanism were calculated combining density functional theory and ab initio simulations. Structures and vibrational frequencies of reactants and transition states were determined at the M062X/6-311+G(d,p) level, while energies were computed at the ROCBS-QB3 level. Rate constants were calculated using transition state theory using the rigid rotor - harmonic oscillator approximation and considering the possible degeneration of internal motions in torsional rotations. The thermodynamic analysis indicated that the Ga gas phase species formed in the highest concentration at the standard GaN deposition temperature (1300 K) is GaNH2, followed by GaH and Ga. The diatomic GaN gas phase species, often considered to be the main precursor to the film growth, is predicted to be unstable with respect to GaNH2. Among the gas phase species containing two Ga atoms, the most stable are GaNHGaH(NH2)3, GaNHGaH2(NH2)2, and GaNHGa(NH2)4, thus indicating that the substitution of the methyl groups of the precursor with H or amino groups is thermodynamically favored. Several kinetic routes leading to the formation of these species were examined. It was found that the condensation of Ga(R1)x(R2)3-x species, with R1 and R2 being either CH3, NH2, or H, is a fast process, characterized by the formation of a precursor state whose decomposition to products requires overcoming submerged energy barriers. It is suggested that these species play a key role in the formation of the first GaN nuclei, whose successive growth leads to the formation of GaN powders. A kinetic analysis performed using a fluid dynamic model allowed us to identify the main reactive routes of this complex system.
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Affiliation(s)
- Stefano Ravasio
- †Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, via Mancinelli 7, 20131 Milano, Italy
| | - Takeshi Momose
- ‡Department of Materials Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Katsushi Fujii
- §School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yukihiro Shimogaki
- ‡Department of Materials Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Masakazu Sugiyama
- §School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Carlo Cavallotti
- †Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, via Mancinelli 7, 20131 Milano, Italy
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15
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Song H, Guo H. Effects of reactant rotational excitations on H2 + NH2 → H + NH3 reactivity. J Chem Phys 2014; 141:244311. [DOI: 10.1063/1.4904483] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Hongwei Song
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
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16
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Song H, Li J, Yang M, Lu Y, Guo H. Nine-dimensional quantum dynamics study of the H2+ NH2→ H + NH3reaction: a rigorous test of the sudden vector projection model. Phys Chem Chem Phys 2014; 16:17770-6. [DOI: 10.1039/c4cp02227k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Oueslati I, Kerkeni B, Spielfiedel A, Tchang-Brillet WÜL, Feautrier N. Ab Initio Investigation of the Abstraction Reactions by H and D from Tetramethylsilane and Its Deuterated Substitutions. J Phys Chem A 2014; 118:791-802. [DOI: 10.1021/jp407310c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- I. Oueslati
- Faculté
des Sciences de Tunis, Département de Physique,
(LPMC), Université de Tunis El Manar, 2092 Tunis, Tunisia
- LERMA,
UMR8112-CNRS, Observatoire de Paris, Université Pierre et Marie Curie, 5 place Jules Janssen, 92195 Meudon Cedex, France
| | - B. Kerkeni
- Faculté
des Sciences de Tunis, Département de Physique,
(LPMC), Université de Tunis El Manar, 2092 Tunis, Tunisia
- Institut Supérieur
des Arts Multimédia de la Manouba, Université de la Manouba, 2010 la Manouba, Tunisia
| | - A. Spielfiedel
- LERMA,
UMR8112-CNRS, Observatoire de Paris, Université Pierre et Marie Curie, 5 place Jules Janssen, 92195 Meudon Cedex, France
| | - W.-Ü L. Tchang-Brillet
- LERMA,
UMR8112-CNRS, Observatoire de Paris, Université Pierre et Marie Curie, 5 place Jules Janssen, 92195 Meudon Cedex, France
| | - N. Feautrier
- LERMA,
UMR8112-CNRS, Observatoire de Paris, Université Pierre et Marie Curie, 5 place Jules Janssen, 92195 Meudon Cedex, France
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18
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Li J, Guo H. A nine-dimensional global potential energy surface for NH4(X2A1) and kinetics studies on the H + NH3 ↔ H2 + NH2 reaction. Phys Chem Chem Phys 2014; 16:6753-63. [DOI: 10.1039/c4cp00241e] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A nine-dimensional global potential energy surface (PES) for the NH4 system is developed from ∼105 high-level ab initio points and the hydrogen abstraction kinetics on the PES agree with experiment.
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Affiliation(s)
- Jun Li
- Department of Chemistry and Chemical Biology
- University of New Mexico
- Albuquerque, USA
| | - Hua Guo
- Department of Chemistry and Chemical Biology
- University of New Mexico
- Albuquerque, USA
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19
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YANG YANG, LIU RUI, WAN RENZHUO, YANG MINGHUI. SEVEN-DIMENSIONAL QUANTUM DYNAMICS STUDY OF THE H2 + NH2 → H + NH3 REACTION ON AN INTERPOLATED POTENTIAL ENERGY SURFACE. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2013. [DOI: 10.1142/s0219633613500545] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Initial-state-selected time-dependent wave packet dynamics studies have been performed for the H 2 + NH 2 → H + NH 3 reaction with a seven-dimensional model on a new interpolated ab initio potential energy surface (PES). The PES is constructed using modified Shepard interpolation Scheme and contains 1967 data points with ab initio calculations carried out on UCCSD(T)/aug-cc-pVTZ level. In the seven-dimensional model, NH 2 group keeps C2v symmetry and two NH bonds are fixed at their equilibrium values. The total reaction probabilities are calculated when (1) the two reactants are initially at their ground states; (2) NH 2 bending mode is excited, and (3) H 2 is on its first vibrational excited state. The integral cross sections are also reported for these initial states with centrifugal-sudden approximation. Thermal rate constants are calculated for the temperature range of 200–2000 K and compared with the previous calculated values and available experimental data. Good agreements between theory and experiments for the rate constants at intermediate temperature are achieved on this PES.
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Affiliation(s)
- YANG YANG
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - RUI LIU
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - RENZHUO WAN
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
- School of Electronic and Electrical Engineering, Wuhan Textile University, Wuhan 430200, P. R. China
| | - MINGHUI YANG
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
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20
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BUCHOWIECKI MARCIN. TI/PIMC METHOD WITH THE TAKAHASHI–IMADA APPROXIMATION FOR THE EQUILIBRIUM CONSTANT OF THE O + HCl ⇌ OH + Cl REACTION. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2013. [DOI: 10.1142/s0219633613500260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The thermodynamic integration/path integral Monte Carlo (TI/PIMC) method of calculating the temperature dependence of the equilibrium constant quantum mechanically is applied to O + HCl ⇌ OH + Cl reaction. The method is based upon PIMC simulations for energies of the reactants and the products and subsequently on thermodynamic integration for the ratios of partition functions. PIMC calculations are performed with the primitive approximation (PA) and the Takahashi–Imada approximation (TIA).
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Affiliation(s)
- MARCIN BUCHOWIECKI
- Institute of Physics, University of Szczecin, Wielkopolska 15, Szczecin, 70-451, Poland
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21
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Constructing Potential Energy Surfaces for Polyatomic Systems: Recent Progress and New Problems. ACTA ACUST UNITED AC 2012. [DOI: 10.1155/2012/164752] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Different methods of constructing potential energy surfaces in polyatomic systems are reviewed, with the emphasis put on fitting, interpolation, and analytical (defined by functional forms) approaches, based on quantum chemistry electronic structure calculations. The different approaches are reviewed first, followed by a comparison using the benchmark H + CH4 and the H + NH3 gas-phase hydrogen abstraction reactions. Different kinetics and dynamics properties are analyzed for these reactions and compared with the available experimental data, which permits one to estimate the advantages and disadvantages of each method. Finally, we analyze different problems with increasing difficulty in the potential energy construction: spin-orbit coupling, molecular size, and more complicated reactions with several maxima and minima, which test the soundness and general applicability of each method. We conclude that, although the field of small systems, typically atom-diatom, is mature, there still remains much work to be done in the field of polyatomic systems.
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22
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Buchowiecki M. Quantum calculations of the temperature dependence of the rate constant and the equilibrium constant for the NH3+H⇌NH2+H2 reaction. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.01.075] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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LIPING JU, RUIFENG LU. COMPARATIVE STUDY OF REACTION RATE CONSTANTS FOR THE NH3 + H → NH2 + H2 REACTION WITH GLOBE DYNAMICS AND TRANSITION STATE THEORIES. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633609005325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The nine-dimension quasi-classical trajectory (QCT) calculations have been carried out for the title reaction with a global potential energy surface (PES) constructed by Corchado and Espinosa-García (J Chem Phys106:4013, 1997). The detailed dynamics calculations cover the specific collision energies falling in the range of 0.62–3.04 eV, which are sufficient to fit the calculated reactive cross-sections into a barrier-type excitation function and to obtain the thermal rate constants. The present QCT rate constants are in good agreement with the recent quantum dynamics (QD) results, both of which are much lower than that of the previous variational transition state theory (VTST).
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Affiliation(s)
- JU LIPING
- Department of Physics, Shenyang Institute of Aeronautical Engineering, Shenyang 110136, P. R. China
| | - LU RUIFENG
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637616, Singapore
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Corchado JC, Espinosa-Garcia J, Yang M. Kinetics and dynamics of the NH3 + H → NH2 + H2 reaction using transition state methods, quasi-classical trajectories, and quantum-mechanical scattering. J Chem Phys 2011; 135:014303. [PMID: 21744898 DOI: 10.1063/1.3605242] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
On a recent analytical potential energy surface developed by two of the authors, an exhaustive kinetics study, using variational transition state theory with multidimensional tunneling effect, and dynamics study, using both quasi-classical trajectory and full-dimensional quantum scattering methods, was carried out to understand the reactivity of the NH(3) + H → NH(2) + H(2) gas-phase reaction. Initial state-selected time-dependent wave packet calculations using a full-dimensional model were performed, where the total reaction probabilities were calculated for the initial ground vibrational state and for four excited vibrational states of ammonia. Thermal rate constants were calculated for the temperature range 200-2000 K using the three methods and compared with available experimental data. We found that (a) the total reaction probabilities are very small, (b) the symmetric and asymmetric N-H stretch excitations enhance the reactivity, (c) the quantum-mechanical calculated thermal rate constants are about one order of magnitude smaller than the transition state theory results, which reproduce the experimental evidence, and (d) quasi-classical trajectory calculations, which were performed with the main goal of analyzing the influence of the zero-point energy problem on the final dynamics results, reproduce the quantum scattering calculations on the same surface.
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Affiliation(s)
- Jose C Corchado
- Departamento de Química Física, Universidad de Extremadura, 06071 Badajoz, Spain.
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Espinosa-García J, Corchado JC. Quasi-Classical Trajectory Calculations of the Hydrogen Abstraction Reaction H + NH3. J Phys Chem A 2010; 114:6194-200. [DOI: 10.1021/jp101607n] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - José C. Corchado
- Departamento de Química Física, Universidad de Extremadura, 06006 Badajoz (Spain)
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Espinosa-Garcia J, Corchado JC. Analytical Potential Energy Surface and Kinetics of the NH3 + H → NH2 + H2 Hydrogen Abstraction and the Ammonia Inversion Reactions. J Phys Chem A 2010; 114:4455-63. [DOI: 10.1021/jp1001513] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - J. C. Corchado
- Departamento de Química Física, Universidad de Extremadura, Spain
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27
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Banks ST, Tautermann CS, Remmert SM, Clary DC. An improved treatment of spectator mode vibrations in reduced dimensional quantum dynamics: Application to the hydrogen abstraction reactions μ+CH4, H+CH4, D+CH4, and CH3+CH4. J Chem Phys 2009; 131:044111. [DOI: 10.1063/1.3177380] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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28
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Ju LP, Han KL, Zhang JZH. Global dynamics and transition state theories: Comparative study of reaction rate constants for gas-phase chemical reactions. J Comput Chem 2009; 30:305-16. [DOI: 10.1002/jcc.21032] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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29
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Banks ST, Clary DC. Chemical reaction surface vibrational frequencies evaluated in curvilinear internal coordinates: Application to H+CH4⇌H2+CH3. J Chem Phys 2009; 130:024106. [DOI: 10.1063/1.3052076] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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Corchado JC, Espinosa-Garcia J. Product vibrational distributions in polyatomic species based on quasiclassical trajectory calculations. Phys Chem Chem Phys 2009; 11:10157-64. [DOI: 10.1039/b912948k] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Yang M. Full dimensional time-dependent quantum dynamics study of the H+NH3→H2+NH2 reaction. J Chem Phys 2008; 129:064315. [DOI: 10.1063/1.2967854] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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32
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Yang M, Corchado JC. Seven dimensional quantum dynamics study of the H2+NH2-->H+NH3 reaction. J Chem Phys 2007; 127:184308. [PMID: 18020640 DOI: 10.1063/1.2790902] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Initial state-selected time-dependent wave packet dynamics calculations have been performed for the H2+NH2-->H+NH3 reaction using a seven dimensional model on an analytical potential energy surface based on the one developed by Corchado and Espinosa-Garcia [J. Chem. Phys. 106, 4013 (1997)]. The model assumes that the two spectator NH bonds are fixed at their equilibrium values and nonreactive NH2 group keeps C2v symmetry and the rotation-vibration coupling in NH2 is neglected. The total reaction probabilities are calculated when the two reactants are initially at their ground states, when the NH2 bending mode is excited, and when H2 is on its first vibrational excited state, with total angular momentum J=0. The converged cross sections for the reaction are also reported for these initial states. Thermal rate constants and equilibrium constants are calculated for the temperature range of 200-2000 K and compared with transition state theory results and the available experimental data. The study shows that (a) the reaction is dominated by ground-state reactivity and the main contribution to the thermal rate constants is thought to come from this state, (b) the excitation energy of H2 was used to enhance reactivity while the excitation of the NH2 bending mode hampers the reaction, (c) the calculated thermal rate constants are very close to the experimental data and transition state theory results at high and middle temperature, while they are ten times higher than that of transition state theory at low temperature (T=200 K), and (d) the equilibrium constants results indicate that the approximations applied may have different roles in the forward and reverse reactions.
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Affiliation(s)
- Minghui Yang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China.
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33
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Eustergerling B, Hèden M, Shi Y. Application of laser induced electron impact ionization to the deposition chemistry in the hot-wire chemical vapor deposition process with SiH4-NH3 gas mixtures. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2007; 18:1950-8. [PMID: 17869128 DOI: 10.1016/j.jasms.2007.08.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Revised: 08/21/2007] [Accepted: 08/21/2007] [Indexed: 05/17/2023]
Abstract
The application of a laser-induced electron impact (LIEI) ionization source in studying the gas-phase chemistry of the SiH(4)/NH(3) hot-wire chemical vapor deposition (HWCVD) system has been investigated. The LIEI source is achieved by directing an unfocused laser beam containing both 118 nm (10.5 eV) vacuum ultraviolet (VUV) and 355 nm UV radiations to the repeller plate in a time-of-flight mass spectrometer. Comparison of the LIEI source with the conventional 118 nm VUV single-photon ionization (SPI) method has demonstrated that the intensities of the chemical species with ionization potentials (IP) above 10.5 eV, e.g., H(2), N(2) and He, have been significantly enhanced with the incorporation of the LIEI source. It is found that the SPI source due to the 118 nm VUV light coexists in the LIEI source. This allows simultaneous observations of parent ions with enhanced intensity from VUV SPI and their "fingerprint" fragmentation ions from LIEI. It is, therefore, an effective tool to diagnose the gas-phase chemical species involved with both NH(3) and SiH(4) in the HWCVD reactor. In using the LIEI source to SiH(4), NH(3) and their mixtures, it has been shown that the NH(3) decomposition is suppressed with the addition of SiH(4) molecules. Examination of the NH(3) decomposition percentage and the time to reach the N(2) and H(2) steady-state intensities for various NH(3)/SiH(4) mixtures suggests that the extent of the suppression is enhanced with more SiH(4) content in the mixture. With increasing filament temperatures, the negative effect of SiH(4) becomes less important.
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34
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Sun X, Cai Z, Feng D, Bian W, Qiao Q, Wang W. The mechanism and kinetics of the HCO + HONO → HCHO + NO 2 reaction — A DFT study. CAN J CHEM 2007. [DOI: 10.1139/v07-044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hydrogen-transfer reaction of HCO + HNO2 → HCHO + NO2 has been studied using both the density function theory (DFT) and high-level ab initio method. Three complete reaction paths have been located for the transfer reaction. Geometry optimization and frequency calculation have been performed at the B3LYP/6-311++G** level. QCISD(T) and G3B3 methods have been used to verify the single-point energy. On the basis of the ab initio data, the rate constants have been deduced over a temperature range of 300–3000 K using the transition-state theory and canonical variational transition-state theory with small-curvature tunneling effect. The calculated rate constants have been compared with the previous reported values.Key words: density function theory, reaction mechanism, variational transition-state theory, rate constant.
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35
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Zhang XQ, Cui Q, Zhang JZH, Han KL. Quantum dynamics study of H+NH3→H2+NH2 reaction. J Chem Phys 2007; 126:234304. [PMID: 17600417 DOI: 10.1063/1.2745796] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We report in this paper a quantum dynamics study for the reaction H+NH3-->NH2+H2 on the potential energy surface of Corchado and Espinosa-Garcia [J. Chem. Phys. 106, 4013 (1997)]. The quantum dynamics calculation employs the semirigid vibrating rotor target model [J. Z. H. Zhang, J. Chem. Phys. 111, 3929 (1999)] and time-dependent wave packet method to propagate the wave function. Initial state-specific reaction probabilities are obtained, and an energy correction scheme is employed to account for zero point energy changes for the neglected degrees of freedom in the dynamics treatment. Tunneling effect is observed in the energy dependency of reaction probability, similar to those found in H+CH4 reaction. The influence of rovibrational excitation on reaction probability and stereodynamical effect are investigated. Reaction rate constants from the initial ground state are calculated and are compared to those from the transition state theory and experimental measurement.
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Affiliation(s)
- Xu Qiang Zhang
- Department of Chemistry, New York University, New York, New York 10003, USA
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36
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Yang M, Corchado JC. Seven-dimensional quantum dynamics study of the H+NH3-->H2+NH2 reaction. J Chem Phys 2007; 126:214312. [PMID: 17567201 DOI: 10.1063/1.2739512] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Initial state-selected time-dependent wave packet dynamics calculations have been performed for the H+NH3-->H2+NH2 reaction using a seven-dimensional model and an analytical potential energy surface based on the one developed by Corchado and Espinosa-Garcia [J. Chem. Phys. 106, 4013 (1997)]. The model assumes that the two spectator NH bonds are fixed at their equilibrium values. The total reaction probabilities are calculated for the initial ground and seven excited states of NH3 with total angular momentum J=0. The converged cross sections for the reaction are also reported for these initial states. Thermal rate constants are calculated for the temperature range 200-2000 K and compared with transition state theory results and the available experimental data. The study shows that (a) the total reaction probabilities are overall very small, (b) the symmetric and asymmetric NH stretch excitations enhance the reaction significantly and almost all of the excited energy deposited was used to reduce the reaction threshold, (c) the excitation of the umbrella and bending motion have a smaller contribution to the enhancement of reactivity, (d) the main contribution to the thermal rate constants is thought to come from the ground state at low temperatures and from the stretch excited states at high temperatures, and (e) the calculated thermal rate constants are three to ten times smaller than the experimental data and transition state theory results.
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Affiliation(s)
- Minghui Yang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China.
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37
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Moscatelli D, Cavallotti C. Theoretical Investigation of the Gas-Phase Kinetics Active during the GaN MOVPE. J Phys Chem A 2007; 111:4620-31. [PMID: 17487990 DOI: 10.1021/jp068318m] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Quantum chemistry investigations have been performed to study the gas-phase chemistry active during the MOVPE of GaN when Ga(CH3)(3) and NH3, diluted in a H2 carrier gas, are used as precursors. Optimized molecular geometries, energies, and transition-state structures of gas-phase species have been determined with density functional theory at the B3LYP/6-311+g(d,p) level. On the basis of the similarity with the soot formation mechanism active during hydrocarbon combustion, we propose that in this system a gas-phase chemistry is active and its reactivity is enhanced by a radical chain mechanism started from methyl radicals. Initiation reactions are surface processes or the pyrolysis of Ga(CH3)(3). A propagation mechanism composed of fast radical reactions, most of which without an activation energy, was identified, and kinetic constants were determined for each step. The proposed mechanism is able to describe the formation of large GaN adducts formed by up to three R-Ga-NH units. These molecules can give fast cyclization reactions that lead to the formation of six-membered cyclic species, which, similar to benzene for combustion, are thermodynamically stable in vast temperature and pressure ranges and can thus be considered as the first GaN nuclei. We also found that the presence of H2 as a carrier gas can greatly enhance the rate of formation of gas-phase particles because it is a major source of atomic hydrogen, a promoter of gas-phase reactivity.
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Affiliation(s)
- Davide Moscatelli
- Dept. di Chimica, Materiali e Ingegneria Chimica G. Natta, Politecnico di Milano, Via Mancinelli 7 - 20131 Milano, Italy
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38
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Wang W, Feng L, Wang W, Luo Q, Li Q. Direct dynamics study on the hydrogen abstraction reaction of CH3CH2F with O(3P). ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.theochem.2006.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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39
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Zhang Q, Wang H, Sun T, Wang W. A theoretical investigation for the reaction of CH3CH2SH with atomic H: Mechanism and kinetics properties. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2005.10.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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40
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Galano A, Cruz-Torres A, Alvarez-Idaboy JR. Isopropylcyclopropane + OH Gas Phase Reaction: A Quantum Chemistry + CVT/SCT Approach. J Phys Chem A 2006; 110:1917-24. [PMID: 16451025 DOI: 10.1021/jp056117x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A theoretical study of the mechanism and kinetics of the OH hydrogen abstraction from isopropylcyclopropane (IPCP) is presented. Optimum geometries, frequencies and gradients have been computed at the BHandHLYP/6-311++G(d,p) level of theory for all stationary points, as well as for additional points along the minimum energy path (MEP). Energies have been improved by single-point calculations at the above geometries using CCSD(T)/6-311++G(d,p) to produce the potential energy surface. The rate coefficients are calculated for the temperature range 260-350 K by using canonical variational theory (CVT) with small-curvature tunneling (SCT) corrections. Our analysis suggests a stepwise mechanism involving the formation of a reactant complex in the entrance channel and a product complex in the exit channel, for all the modeled paths. The reactant complexes are examined in detail, because they exhibit alkene-like structure. The excellent agreement between the overall calculated and experimental rate coefficients at 298 K supports the reliability of the parameters obtained for the temperature dependence and branching ratios of the IPCP + OH reaction, proposed here for the fist time. The expression that best describes the studied reaction is k(overall) = 6.15 x 10(-13)e1747/RT cm3 x molecule(-1) x s(-1). The predicted activation energy is -0.89 kcal/mol.
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Affiliation(s)
- Annia Galano
- Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas 152, 07730 México D. F., México.
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41
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Abstract
This essay provides a perspective on several issues in valence bond theory: the physical significance of semilocal bonding orbitals, the capability of valence bond concepts to explain systems with multireferences character, the use of valence bond theory to provide analytical representations of potential energy surfaces for chemical dynamics by the method of semiempirical valence bond potential energy surfaces (an early example of specific reaction parameters), by multiconfiguration molecular mechanics, by the combined valence bond-molecular mechanics method, and by the use of valence bond states as coupled diabatic states for describing electronically nonadiabatic processes (photochemistry). The essay includes both ab initio and semiempirical approaches.
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Affiliation(s)
- Donald G Truhlar
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota 55455-0431, USA.
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42
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Zhang Q, Zhang RQ, Chan KS, Bello I. Ab Initio and Variational Transition State Approach to β-C3N4 Formation: Kinetics for the Reaction of CH3NH2 with H. J Phys Chem A 2005; 109:9112-7. [PMID: 16332019 DOI: 10.1021/jp0531661] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The CH3NH2 molecule has been considered as either an important intermediate in methane and ammonia mixtures or a precursor in methylamine and hydrogen mixtures in the synthesis of carbon nitride thin films. The fast Hydrogen (H) abstraction from CH3NH2 is an important process involved in the formation of HCN or CNH in the chemical vapor deposition (CVD) of carbon nitride thin films. The energetic and kinetic characteristics of the H abstraction reaction from CH3NH2 by atomic H used in CVD of beta-C3N4 were studied using ab initio direct dynamics methods for the first time. Two primary processes were identified for this reaction: H abstraction from the CH3 group and H abstraction from the NH2 group. On the basis of ab initio data, the rate constants of each channel have been deduced by canonical variational transition state theory with small-curvature tunneling correction over a wide temperature range of 200 to approximately 3000 K. The theoretical results were compared with available experimental data.
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Affiliation(s)
- Qingzhu Zhang
- Center of Super-Diamond and Advanced Films and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, China
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43
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Interpolated potential energy surface for abstraction and exchange reactions of NH3 + H and deuterated analogues. Theor Chem Acc 2005. [DOI: 10.1007/s00214-004-0626-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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44
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Galano A, Alvarez-Idaboy JR, Ruiz-Santoyo ME, Vivier-Bunge A. Glycolaldehyde + OH Gas Phase Reaction: A Quantum Chemistry + CVT/SCT Approach. J Phys Chem A 2004; 109:169-80. [PMID: 16839103 DOI: 10.1021/jp047490s] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We present a theoretical study of the mechanism and kinetics of the OH hydrogen abstraction from glycolaldehyde. Optimum geometries, frequencies, and gradients have been computed at the BHandHLYP/6-311++G(d,p) level of theory for all stationary points, as well as for additional points along the minimum energy path (MEP). Energies are obtained by single-point calculations at the above geometries using CCSD(T)/6-311++G(d,p) to produce the potential energy surface. The rate coefficients are calculated for the temperature range 200-500 K by using canonical variational theory (CVT) with small-curvature tunneling (SCT) corrections. Our analysis suggests a stepwise mechanism involving the formation of a reactant complex in the entrance channel and a product complex in the exit channel, for all the modeled paths. The overall agreement between the calculated and experimental kinetic data that are available at 298 K is very good. This agreement supports the reliability of the parameters obtained for the temperature dependence of the glycolaldehyde + OH reaction. The expressions that best describe the studied reaction are k(overall) = 7.76 x 10(-13) e(1328/)(RT) cm(3).molecule(-1).s(-1) and k(overall) = 1.09 x 10(-21)T(3.03) e(3187/)(RT) cm(3) molecule(-1) s(-1), for the Arrhenius and Kooij approaches, respectively. The predicted activation energy is (-1.36 +/- 0.03) kcal/mol, at about 298 K. The agreement between the calculated and experimental branching ratios is better than 10%. The intramolecular hydrogen bond in OO-s-cis glycolaldehyde is found to be responsible for the discrepancies between SAR and experimental rate coefficients.
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Affiliation(s)
- Annia Galano
- Instituto Mexicano del Petróleo, Eje Central Lazaro Cardenas 152, 007730 México D. F., México.
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45
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Espinosa-Garciá J, Rangel C, Navarrete M, Corchado JC. New hybrid method for reactive systems from integrating molecular orbital or molecular mechanics methods with analytical potential energy surfaces. J Chem Phys 2004; 121:5098-108. [PMID: 15352801 DOI: 10.1063/1.1784448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A computational approach to calculating potential energy surfaces for reactive systems is presented and tested. This hybrid approach is based on integrated methods where calculations for a small model system are performed by using analytical potential energy surfaces, and for the real system by using molecular orbital or molecular mechanics methods. The method is tested on a hydrogen abstraction reaction by using the variational transition-state theory with multidimensional tunneling corrections. The agreement between the calculated and experimental information depends on the quality of the method chosen for the real system. When the real system is treated by accurate quantum mechanics methods, the rate constants are in excellent agreement with the experimental measurements over a wide temperature range. When the real system is treated by molecular mechanics methods, the results are still good, which is very encouraging since molecular mechanics itself is not at all capable of describing this reactive system. Since no experimental information or additional fits are required to apply this method, it can be used to improve the accuracy of molecular orbital methods or to extend the molecular mechanics method to treat any reactive system with the single constraint of the availability of an analytical potential energy surface that describes the model system.
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47
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Theoretical study on the reaction path dynamics and rate constants for the hydrogen-abstraction reaction of atomic O (3P) with CH2FCl. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2003.11.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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48
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Zhang Q, Wang S, Gu Y. A theoretical investigation on the mechanism and kinetics for the reaction of atomic O(3P) with CH3CHCl2. J Chem Phys 2003. [DOI: 10.1063/1.1622928] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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49
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Barreto PR, Vilela AF, Gargano R. A simple program to determine the reaction rate and thermodynamic properties of reacting system. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/j.theochem.2003.08.098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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50
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Barreto PR, Vilela AF, Gargano R. A simple program to determine the reaction rate and thermodynamic properties of reacting system. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/j.theochem.2003.08.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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