This presentation has been moved. To view this presentation, please visit http://pubs.acs.org/iapps/liveslides/pages/index.htm?mscNo=jz301064w Quantum Dynamics of the HO + CO H + CO2 Reaction on an Accurate Potential Energy Surface

1. Quantum Dynamics of the HO + CO → H + CO2
Reaction on an Accurate Potential Energy Surface
Jianyi Ma, Jun Li, and Hua Guo*
Department of Chemistry and Chemical Biology, University of New Mexico,
Albuquerque, New Mexico 87131, United States
*E-mail: hguo@unm.edu.
J. Phys. Chem. Lett. 2012, Vol. 3, 2482 -2486 1

2. Motivations
 HO+COHOCOH+CO2 is one of most important combustion reactions.
 Previous attempts to elucidate reaction dynamics were hampered by
inaccuracies in potential energy surface.
 Accurate quantum dynamics is necessary because of tunneling, but
challenging due to heave atoms and deep wells.
 Globally accurate PES:
Base on ~35000
UCCSD(T)
F12b/AVTZ points.
JCP, 136, 041103 (2012)
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3. Results
Quantum reaction probability (J=0):
 Small but monotonically increasing reaction probability.
 Enhancement by OH vibrational excitation.
 Tunneling important as PQCT<PQM at lower collision energy.
 The complex forming reaction experiences bottlenecks in both
entrance and exit channels.
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4. Results
Rate constant (J-shifting approximation):
 Better agreement with experimental data than that on an earlier
(LTSH) potential energy surface, due apparently to improvement in
potential energy surface
 In reasonable agreement with QCT results.
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5. Conclusions
Full-dimensional quantum scattering
calculations on the new ab-initio-based HOCO
PES yield a better agreement with experimental
rate constants. They also confirm the promotional
effect of the OH vibrational excitation on the
reactivity and the importance of tunneling in this
reaction. This work paves the way for more
extensive quantum scattering calculations that
would include J > 0 partial waves and possibly
final-state resolution.
Acknowledgments
This work was funded by Department of
Energy (DE-FG02-05ER15694). We thank J. M.
Bowman and D. H. Zhang for stimulating
discussions.
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