Damping of total differential cross sections: Observations and empirical anisotropic potentials for HeC/sub 2/H/sub 2/ and HeOCS

Journal Article · Wed Jul 01 04:00:00 EDT 1987 · J. Chem. Phys.; (United States)

OSTI ID:6494781

Danielson, L J; McLeod, K M; Keil, M

Differential cross section (DCS) measurements are reported for scattering of a He atomic beam by crossed beams of Ar, C/sub 2/H/sub 2/, CO/sub 2/, and OCS. Relative to the HeAr diffractive structure, the HeC/sub 2/H/sub 2/ DCS is moderately damped at small scattering angles and severely damped at large scattering angles; the HeCO/sub 2/ and HeOCS DCS's are severely damped for all scattering angles. This damping directly reflects increasing anisotropy of the scattering partner from Ar (none) to C/sub 2/H/sub 2/ (moderate) to CO/sub 2/ and OCS (strong). Even though the present data do not resolve elastic from inelastic contributions, the HeCO/sub 2/ results are consistent with partially resolved inelastic DCS measurements (U. Buck, H. Meyer, M. Tolle, and R. Schinke, Chem. Phys. 104, 345 (1986)) and therefore complement them. Consequently the data are used to obtain empirical anisotropic intermolecular potentials for HeC/sub 2/H/sub 2/ and HeOCS within the infinite-order-sudden approximation. These reproduce the total (unresolved elastic +inelastic) DCS measurements very well, even though the angular asymmetry of OCS is ignored in the analysis.

• Research Organization: Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
• OSTI ID: 6494781
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 87:1; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ACETYLENE
ALKYNES
ARGON
ATOM COLLISIONS
ATOM-ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
ATOMIC BEAMS
BEAMS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBON OXYSULFIDE
CHALCOGENIDES
COLLISIONS
CROSS SECTIONS
DAMPING
DIFFERENTIAL CROSS SECTIONS
ELEMENTS
FLUIDS
GASES
HELIUM
HYDROCARBONS
INTERMOLECULAR FORCES
MOLECULAR BEAMS
MOLECULE COLLISIONS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POTENTIALS
RARE GASES
SULFUR COMPOUNDS