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Updated: Jun 20, 2026
09:16
Reaction Kinetics and Combustion Dynamics of I4O9 and Aluminum Mixtures
Published on: November 7, 2016
Toward Quantitative Reaction Dynamics of O3.
Raidel Martin Barrios1, Abhirami Vijayakumar1, Jingchun Wang1
1Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.
The Journal of Physical Chemistry Letters
|June 18, 2026
Summary
This study characterizes O(3P) + O2 collisions using a detailed potential energy surface. It accurately captures isotope exchange rate temperature dependence, improving upon prior simulations.
Area of Science:
- Chemical Physics
- Quantum Chemistry
- Atmospheric Chemistry
Background:
- Ozone (O3) formation and destruction are critical atmospheric processes.
- Understanding the dynamics of oxygen atom and molecule collisions is essential for atmospheric modeling.
- Previous theoretical studies of O + O2 reactions had limitations in accuracy and scope.
Purpose of the Study:
- To characterize the reaction dynamics of O(3P) + O2(3Σg-) collisions.
- To develop and utilize a high-level ab initio potential energy surface (PES) for accurate simulations.
- To investigate isotope effects in atom exchange reactions and dissociation pathways.
Main Methods:
- High-level multi-reference configuration interaction with single and double excitations plus a perturbative estimate of quadruple excitations (MRCI+Q) calculation with an augmented correlation-consistent basis set of quadruple zeta quality (aug-cc-pVQZ) was employed.
- The potential energy surface (PES) was represented using a reproducing kernel Hilbert space method.
- Quantum dynamics calculations were performed to determine reaction rates and temperature dependencies for isotopic variants of oxygen.
Main Results:
- The calculated rates for O(16O) + O2 and O(18O) + O2 atom exchange reactions showed a negative temperature dependence, consistent with experimental observations.
- The ratio of isotopic exchange rates R(T) = k8exch(T)/k6exch(T) was accurately reproduced, exhibiting a maximum around 300 K.
- Dissociation reaction rates were improved, being lower by approximately one order of magnitude compared to experiments, and suggesting an electronic degeneracy factor gediss favoring lower values.
Conclusions:
- The study provides a more accurate theoretical description of O + O2 collision dynamics.
- Discrepancies with experimental absolute rates are attributed mainly to the neglect of zero-point energy effects.
- Nonadiabatic effects are found to have a minimal impact on the atom-exchange reaction dynamics.
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