Global minimum profile error (GMPE) – a least-squares-based approach for extracting macroscopic rate coefficients for complex gas-phase chemical reactions

2018 ◽  
Vol 20 (2) ◽  
pp. 1231-1239 ◽  
Author(s):  
Minh v. Duong ◽  
Hieu T. Nguyen ◽  
Tam V.-T. Mai ◽  
Lam K. Huynh
Keyword(s):  
Master Equation ◽  
Least Squares ◽  
Gas Phase ◽  
Chemical Reactions ◽  
Global Minimum ◽  
Rate Coefficients ◽  
Gas Phase Reactions ◽  
Profile Error ◽  
Time Resolved ◽  
Phase Chemical

The new GMPE method was introduced to derive the macroscopic rate coefficients for complex gas-phase reactions from the time-resolved species profiles obtained from the master equation (ME) solutions.

scholarly journals Automated calculation of thermal rate coefficients using ring polymer molecular dynamics and machine-learning interatomic potentials with active learning

2018 ◽  
Vol 20 (46) ◽  
pp. 29503-29512 ◽  
Author(s):  
I. S. Novikov ◽  
Y. V. Suleimanov ◽  
A. V. Shapeev
Keyword(s):  
Machine Learning ◽  
Molecular Dynamics ◽  
Active Learning ◽  
Gas Phase ◽  
Chemical Reactions ◽  
Rate Coefficients ◽  
Interatomic Potentials ◽  
Ring Polymer ◽  
Ring Polymer Molecular Dynamics ◽  
Phase Chemical

We propose a methodology for the fully automated calculation of thermal rate coefficients of gas phase chemical reactions, which is based on combining ring polymer molecular dynamics (RPMD) and machine-learning interatomic potentials actively learning on-the-fly.

Time-resolved IR chemiluminescence in gas-phase chemical kinetics

1999 ◽  
Vol 68 (3) ◽  
pp. 171-181 ◽  
Author(s):  
Evgenii N Chesnokov ◽  
Viktor N Panfilov
Keyword(s):  
Gas Phase ◽  
Chemical Kinetics ◽  
Time Resolved ◽  
Phase Chemical

scholarly journals Experimental and computational kinetics investigations for the reactions of Cl atoms with series of unsaturated ketones in gas phase

2017 ◽  
Author(s):  
Siripina Vijayakumar ◽  
Avinash Kumar ◽  
Balla Rajakuma
Keyword(s):  
Gas Phase ◽  
State Theory ◽  
Rate Coefficients ◽  
Gas Phase Reactions ◽  
Temperature Dependent ◽  
Unsaturated Ketones ◽  
Temperature Range ◽  
Computational Calculations ◽  
Temperature Rate ◽  
Cl Atoms

Abstract. Temperature dependent rate coefficients for the gas phase reactions of Cl atoms with 4-hexen-3-one and 5-hexen-2-one were measured over the temperature range of 298–363 K relative to 1-pentene, 1,3-butadiene and isoprene. Gas Chromatography (GC) was used to measure the concentrations of the organics. The derived temperature dependent Arrhenius expressions are k4-hexen-3-one+Cl (298–363 K) = (2.82 ± 1.76)×10−12exp [(1556 ± 438)/T] cm3 molecule−1 s−1 and k5-hexen-2-one+Cl (298–363 K) = (4.6 ± 2.4)×10−11exp[(646 ± 171)/T] cm3 molecule−1 s−1. The corresponding room temperature rate coefficients are (5.54 ± 0.41)×10−10 cm3 molecule−1 s−1 and (4.00 ± 0.37)×10−10 cm3 molecule−1 s−1 for the reactions of Cl atoms with 4-hexen-3-one and 5-hexen-2-one respectively. To understand the mechanism of Cl atom reactions with unsaturated ketones, computational calculations were performed for the reactions of Cl atoms with 4-hexen-3-one, 5-hexen-2-one and 3-penten-2-one over the temperature range of 275–400 K using Canonical Variational Transition state theory (CVT) with Small Curvature Tunneling (SCT) in combination with CCSD(T)/6-31+G(d, p)//MP2/6-311++G(d, p) level of theory. Atmospheric implications, reaction mechanism and feasibility of the title reactions are discussed in this manuscript.

The Role of Starting Potential in the Kinetics of Chemical Reactions under Electrodeless Discharge

1970 ◽  
Vol 25 (11) ◽  
pp. 1772
Author(s):  
T.S.R Ao ◽  
A. Patil
Keyword(s):  
Gas Phase ◽  
Chemical Reactions ◽  
Electric Discharge ◽  
Specific Rate ◽  
Gas Phase Reactions ◽  
Electrodeless Discharge ◽  
First Order ◽  
Kinetics Of

Abstract It has been shown that in kinetically first order gas phase reactions occuring under electric discharge, such as the decomposition of N2O, the application, at various initial pressures, of the same multiple of the respective starting potential ensures that the reaction occurs at the same specific rate.

scholarly journals Astrochemistry of Interstellar Clouds: II. Molecular Formation in a Contracting Cloud

1987 ◽  
Vol 120 ◽  
pp. 273-274
Author(s):  
M.A. El Shalaby ◽  
A. Aiad
Keyword(s):  
Gas Phase ◽  
Optical Depth ◽  
Chemical Reactions ◽  
Particle Density ◽  
Interstellar Cloud ◽  
Gas Phase Reactions ◽  
Interstellar Clouds ◽  
Continous Function ◽  
Molecular Formation ◽  
Self Gravity

The chemistry of an 667 Mo interstellar cloud was studied using 142 reactions for 40 species during the contraction under self gravity in two steps. At first the contraction is allowed without gas phase reactions untill certain optical depth is reached. Secondly, at this optical depth the chemical reactions are started for sufficient cycles in a time dependant scheme till only very small additionally changes in the abundances occur. The so obtained, relative abundances and coulmn densities for different species represent a continous function of the optical depths. The values arround τ=6.3 represent the observations for H2, H2+, H3+, OH, OH+, CH, CH+, CH2, CH2+, CH3+, H2O and H3O+. The region of τ between 1 and 5 i.e. of particle density between 4 102–6 103 is the preferable formation place for the majority of molecules.

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