Uniform semiclassical sudden approximation for rotationally inelastic scattering

Journal Article · Fri Aug 01 04:00:00 EDT 1980 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.440232· OSTI ID:5296447

Korsch, H J; Schinke, R

The infinite-order-sudden (IOS) approximation is investigated in the semiclassical limit. A simplified IOS formula for rotationally inelastic differential cross sections is derived involving a uniform stationary phase approximation for two-dimensional oscillatory integrals with two stationary points. The semiclassical analysis provides a quantitative description of the rotational rainbow structure in the differential cross section. The numerical calculation of semiclassical IOS cross sections is extremely fast compared to numerically exact IOS methods, especially if high ..delta..j transitions are involved. Rigid rotor results for He--Na/sub 2/ collisions with ..delta..j< or approx. =26 and for K--CO collisions with ..delta..j< or approx. =70 show satisfactory agreement with quantal IOS calculations.

• Research Organization: Fachbereich Physik, Universitaet Kaiserslautern, D-6750 Kaiserslautern, West Germany
• OSTI ID: 5296447
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 73:3; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular &amp; Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COLLISIONS
CROSS SECTIONS
CRYOGENIC FLUIDS
DIFFERENTIAL CROSS SECTIONS
DIMERS
ELEMENTS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
FLUIDS
HELIUM
METALS
MOLECULE COLLISIONS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
POTASSIUM
RARE GASES
ROTATIONAL STATES
SEMICLASSICAL APPROXIMATION
SODIUM
SUDDEN APPROXIMATION