Application of scaling theory to vibrational relaxation in linear anharmonic triatomic molecules
The energy-corrected-sudden (ECS) scaling theory is extended to vibrational relaxation in the collisions of anharmonic linear triatomic molecules with atoms. Application is made to the collisions of He atoms with /sup 12/C /sup 16/O/sub 2/, /sup 14/C /sup 16/O/sub 2/, and /sup 12/C /sup 18/O/sub 2/. By combining the rate constants for the (01/sup 1/0 ..-->.. 00/sup 0/0) transitions, calculated using the vibrational close-coupling rotational infinite-order-sudden (VCC-IOS) method, with the ECS scaling theory, we predict rate constants for the transitions (10/sup 0/0 ..-->.. 01/sup 1/0), (02/sup 2/0 ..-->.. 01/sup 1/0) and (02/sup 0/0 ..-->.. 01/sup 1/0). These agree very well with the rate constants computed directly using the VCC-IOS technique. This comparison presents a particularly severe test of the accuracy of the ECS scaling theory for anharmonic polyatomics since Fermi resonance effects are large for the 10/sup 0/0 and 02/sup 0/0 levels in CO/sub 2/.
- Research Organization:
- Department of Chemistry, University of Manchester Institute of Science and Technology, Manchester M60 1QD, United Kingdom
- OSTI ID:
- 5837269
- Journal Information:
- J. Chem. Phys.; (United States), Vol. 79:5
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ATOM-MOLECULE COLLISIONS
SCALING LAWS
CARBON 14
ISOTOPE EFFECTS
CARBON DIOXIDE
HELIUM
OXYGEN 18
ENERGY-LEVEL TRANSITIONS
RELAXATION
SUDDEN APPROXIMATION
VIBRATIONAL STATES
ATOM COLLISIONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON COMPOUNDS
CARBON ISOTOPES
CARBON OXIDES
CHALCOGENIDES
COLLISIONS
ELEMENTS
ENERGY LEVELS
EVEN-EVEN NUCLEI
EXCITED STATES
FLUIDS
GASES
ISOTOPES
LIGHT NUCLEI
MOLECULE COLLISIONS
NONMETALS
NUCLEI
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
RADIOISOTOPES
RARE GASES
STABLE ISOTOPES
YEARS LIVING RADIOISOTOPES
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena