Properties of Feshbach and “shape”-resonances in ozone and their role in recombination reactions and anomalous isotope effects
- Marquette Univ., Milwaukee, WI (United States)
Computational modelling of recombination reactions that form ozone require the inclusion of several quantum mechanical effects such as symmetry, zero-point energy, scattering resonances and tunneling. Major elements of theory for rigorous description of this process are reviewed, with emphasis on interpreting the famous anomalous isotope effect due to substitutions of 18O. In this work, three reaction pathways, for the formation of symmetric and asymmetric isotopologues of ozone, are introduced and a hierarchy of theory levels is outlined. Lower levels of theory are used to account for the effects of symmetry, isotope mass, rotational excitations and vibrational zero-point energy differences. They happen to be equivalent to statistical descriptions of the process and do not show anomalous isotope effects. Properties of scattering resonances should be included at the next level of theory, and may finally explain the isotope effect. Shape resonances, trapped behind the centrifugal barrier and populated by tunneling, can be studied by neglecting couplings between the diabatic ro-vibrational states of the system. Inclusion of these couplings enables the formation of Feshbach resonances. Accurate calculations using hyper-spherical coordinates are performed to obtain resonance energies, lifetimes and wavefunctions. Differences between the shape resonances and Feshbach resonances are emphasized.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE; National Science Foundation (NSF)
- Grant/Contract Number:
- AGS-1252486; AC02-05CH11231
- OSTI ID:
- 1544272
- Journal Information:
- Faraday Discussions, Vol. 212; ISSN 1359-6640
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Use of Isotope Effects To Understand the Present and Past of the Atmosphere and Climate and Track the Origin of Life
|
journal | February 2019 |
Use of Isotope Effects To Understand the Present and Past of the Atmosphere and Climate and Track the Origin of Life
|
journal | May 2019 |
Several levels of theory for description of isotope effects in ozone: Effect of resonance lifetimes and channel couplings
|
journal | October 2018 |
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