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Multiconfiguration time-dependent Hartree approach to study the OH + H2 reaction
Sayak Bhattacharya1, Aditya N Panda, Hans-Dieter Meyer
1Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India. sayak@iitg.ernet.in
The Journal of Chemical Physics
|June 10, 2010
Summary
Full dimensional quantum scattering calculations reveal significant differences in OH + H2 reaction cross sections between two potential energy surfaces. The multiconfiguration time-dependent Hartree method accurately predicted these variations, highlighting surface-dependent reactivity.
Area of Science:
- Chemical Physics
- Quantum Chemistry
- Theoretical Chemistry
Background:
- The OH + H2 reaction is a fundamental process in combustion and atmospheric chemistry.
- Accurate theoretical modeling is crucial for understanding reaction dynamics and kinetics.
- Previous studies have explored this reaction on various potential energy surfaces.
Purpose of the Study:
- To perform full dimensional quantum scattering calculations for the OH + H2 reaction.
- To compare reaction dynamics on the Walch-Dunning-Schatz-Elgersma (WDS) and Yang-Zhang-Collins-Lee (YZCL) potential energy surfaces.
- To investigate the influence of different potential energy surfaces on reaction probabilities and cross sections.
Main Methods:
- Utilized full dimensional quantum scattering calculations.
- Employed the multiconfiguration time-dependent Hartree (MCTDH) method for wave packet propagation.
- Used an exact form of the kinetic energy operator for high accuracy.
Main Results:
- Reaction probabilities and cross sections were computed on both WDS and YZCL surfaces.
- Results from the MCTDH method showed good agreement with previous theoretical findings.
- Significant differences in cross sections were observed between the two surfaces as a function of translational energy.
Conclusions:
- The MCTDH method is an efficient and accurate approach for large-scale quantum dynamics.
- Differences in barrier heights and transition state structures between the WDS and YZCL surfaces explain the observed variations in reaction probabilities.
- Potential energy surface choice critically impacts the predicted dynamics of the OH + H2 reaction.
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