Theoretical studies of tunneling processes in three-body exchange reactions of van der Waals rare gas dimers

Journal Article · Sat Mar 31 23:00:00 EST 1984 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.447117· OSTI ID:5004983

Turner, R A; Raff, L M; Thompson, D L

Rare gas atom--diatom collisions of Ar+Ar/sub 2/, Xe+Ar/sub 2/, Kr+Xe/sub 2/, Kr+Ne/sub 2/, and Kr+NeAr have been investigated to determine the importance of tunneling processes in exchange and dissociation reactions involving van der Waals molecules. Reaction cross sections, angular distributions, and product-energy distributions have been computed using Monte Carlo quasiclassical trajectories. The effect of tunneling through the rotational barrier upon these quantities has been computed using WKB methods. The results show that metastable diatomic products with energies above the classical dissociation limit, but below the rotational barrier, play a significant role in the dynamics of both exchange and dissociation reactions. Lifetime distributions of such metastable dimers illustrate their importance in crossed molecular beam studies of rare gas systems. The WKB calculations indicate that a significant, and possibly measurable, number of the metastables dissociate by tunneling before they would reach the detector in a molecular beam experiment. Close agreement has been found between these calculations and statistical state-counting calculations of metastable product dimer lifetimes. Experiments are suggested that might permit the direct observation of tunneling in these systems.

• Research Organization: Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078
• OSTI ID: 5004983
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 80:7; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
ARGON
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
CHEMICAL REACTIONS
COLLISIONS
CROSS SECTIONS
DIMERS
DISSOCIATION
DISTRIBUTION
ELEMENTS
FLUIDS
GASES
KRYPTON
MOLECULE COLLISIONS
NEON
NONMETALS
RARE GASES
TUNNEL EFFECT
VAN DER WAALS FORCES
WKB APPROXIMATION
XENON