Accession Number:

ADA445201

Title:

Quantum and Quasi-Classical Studies of the O(3P) + HCl yields OH + Cl(2P) Reaction Using Benchmark Potential Surfaces (PREPRINT)

Descriptive Note:

Technical paper

Corporate Author:

EMORY UNIV ATLANTA GA DEPT OF CHEMISTRY

Report Date:

2004-07-25

Pagination or Media Count:

39.0

Abstract:

We have performed quantum mechanical QM dynamics calculations within the independent-state approximation with new benchmark triplet A and A surfaces B. Ramachandran et al. J. Chem. Phys. 119, 9590 2003. for the ro-vibronic state-to-state measurements of the reaction O3P HClv2,j1,6,9 61614 OHv j Cl2P Zhang et al. J. Chem. Phys. 94, 2704 1991. The QM and experimental rotational distributions peak at similar OHj levels, but the QM distributions are significantly narrower than the measurements and previous quasi-classical dynamics studies. The OHlow j populations observed in the measurements are nearly absent in the QM results. We have also performed quasi-classical trajectory with histogram binning QCT-HB calculations on these same benchmark surfaces. The QCT-HB rotational distributions, which are qualitatively consistent with measurements and classical dynamics studies using other surfaces, are much broader than the QM results. Application of a Gaussian binning correction QCT-GB dramatically narrows and shifts the QCT-HB rotational distributions to be in very good agreement with the QM results. The large QCT-GB correction stems from the special shape of the joint distribution of the classical rotationalvibrational action of OH products. We have also performed QM and QCT calculations for the transition, O HClv0,T300 K 61614 OHv j Cl from threshold to 130 kcal mol-1 collision energy as a guide for possible future hyperthermal O-atom measurements. We find in general a mixed energy release into translation and rotation consistent with a late barrier to reaction. Angular distributions at high collision energy are forward peaked, consistent with a stripping mechanism. Direct collisional excitation channel cross sections, O HClv0,T300 61614 O HClv 1, in the same energy range are large, comparable in

Subject Categories:

  • Physical Chemistry
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE