Classical two-dimensional model for rotational-vibrational atom--diatom inelastic scattering

Journal Article · Wed Sep 15 04:00:00 EDT 1982 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.444215· OSTI ID:5016831

Serri, J A; Bilotta, R M; Pritchard, D E

The classical hard ellipse model for atom--diatom rotationally inelastic (RI) collisions is generalized to include simultaneous vibrational excitation by assuming that this excitation is proportional to the square of the component of momentum transferred along the major axis of the ellipse. Calculations are presented which compare level-to-level RI angular distributions of vibrationally elastic (..delta..v = 0) and vibrationally inelastic (..delta..v = 1) scattering. These calculations reproduce the main features observed in recent measurements of level-to-level rovibrationally inelastic scattering for Na/sub 2/ with Ar. With ..delta..v = 0 and 1, the scattering distributions display rainbow structure whose angular position increases nearly linearly with ..delta..j. In addition, the ..delta..v = 1 scattering shows considerable suppression of small angle scattering (which also has small ..delta..j). We emphasize that this suppression of forward scattering results from a kinematic exclusion of small angle scattering for impulsive inelastic collisions with a slowly rotating molecule irrespective of the origin of inelasticity.

• Research Organization: Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• OSTI ID: 5016831
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 77:6; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
ARGON
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
COLLISIONS
DIMERS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FLUIDS
GASES
INELASTIC SCATTERING
MATHEMATICAL MODELS
METALS
MOLECULE COLLISIONS
NONMETALS
RARE GASES
ROTATIONAL STATES
SCATTERING
SODIUM
TWO-DIMENSIONAL CALCULATIONS
VIBRATIONAL STATES