Non-adiabatic effects in F + CHD3 reactive scattering.
1Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Sáenz Peña 352, Bernal B1876BXD, Argentina.
The Journal of Chemical Physics
|June 10, 2017
Summary
Non-adiabatic transitions significantly impact fluorine atom reactions with methane isotopologues. Including these transitions does not resolve theoretical and experimental discrepancies for F + CHD3 reactions.
Area of Science:
- Chemical Dynamics
- Quantum Chemistry
- Reaction Kinetics
Background:
- Investigating the F + CHD3 reaction is crucial for understanding polyatomic molecule dynamics.
- Non-adiabatic effects, including vibronic and spin-orbit coupling, play a significant role in chemical reactions.
Purpose of the Study:
- To investigate the influence of non-adiabatic transitions on the F + CHD3 → DF + CHD2 and F + CHD3 → HF + CD3 reactions.
- To adapt computational methods for simulating reactions with complex potential energy surfaces.
Main Methods:
- Simulating nuclear dynamics using trajectory surface hopping.
- Employing a vibronically and spin-orbit coupled diabatic potential energy matrix.
- Adapting Tully's fewest switching algorithm for complex diabatic potentials.
Main Results:
- Non-adiabatic cross sections are 1.4–2.1 times smaller than adiabatic ones for F(2P3/2) + CHD3.
- Reactivity of CHD3(ν1=1) is higher than CHD3(ν1=0), primarily due to the HF + CD3 channel.
- Cross sections for F(2P1/2) reactions are substantially smaller than for F(2P3/2).
Conclusions:
- Non-adiabatic transitions are essential for accurate theoretical descriptions of the F + CHD3 reaction.
- The inclusion of non-adiabatic effects does not reconcile existing theoretical and experimental disagreements.
- Vibrational excitation and spin-orbit state of fluorine significantly influence reaction outcomes.
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