Reduced Dimensionality Quantum Dynamics of CH3 + CH4 -> CH4 + CH3: Symmetric Hydrogen Exchange on an Ab Initio Potential.
J PHYS CHEM A
4255 - 4264.
The symmetric title reaction CH3 + CH4 -> CH4 + CH3 is studied using quantum scattering theory. Quantum dynamics calculations are performed in hyperspherical coordinates with a two-dimensional effective potential energy surface consisting of an analytical 18-parameter double Morse function fit to ab initio data at the CCSD(T)/cc-pVTZ//MP2/cc-pVTZ level of theory. Spectator modes are treated adiabatically by inclusion of projected zero-point energy corrections in the effective potential. The close-coupled equations are solved via R-matrix propagation. Energy and J-shifted thermal rate constants are compared to experimental data and highlight the importance of quantum tunneling. Oscillating reactivity and metastable bound state resonances are observed in the cumulative and state-to-state reaction probabilities. State-to-state differential and initial state-selected integral cross sections are presented and discussed. Primary and secondary kinetic isotope effects for two symmetric deuterated variants of the title reaction are also presented.
|Title:||Reduced Dimensionality Quantum Dynamics of CH3 + CH4 -> CH4 + CH3: Symmetric Hydrogen Exchange on an Ab Initio Potential|
|Keywords:||COMPARATIVE ELECTRONIC ANALYSIS, TRANSITION-STATE THEORY, REACTIVE SCATTERING, ABSTRACTION REACTIONS, HYDROGEN ABSTRACTION, CHEMICAL-REACTIONS, CH4/CH3-SYSTEMS, H-ATOMS, METHANE, METHYL|
|UCL classification:||UCL > School of BEAMS > Faculty of Engineering Science
UCL > School of BEAMS > Faculty of Engineering Science > Engineering Science Faculty Office
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