Rotational predissociation dynamics of OH--Ar ([ital A] [sup 2][Sigma][sup +]) using the finite range scattering wave function method
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323 (United States)
- Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)
Predissociative resonances of OH--Ar are computed up to 300 cm[sup [minus]1] above the Ar+OH ([ital A] [sup 2][Sigma][sup +], [ital v]=0, [ital j]=0) asymptote for total (rotational) angular momentum states [ital J][le]10. The energies, lifetimes, and OH [ital A] [sup 2][Sigma][sup +] product rotational distributions of the predissociative resonances are calculated using a numerical method based on the energy independent integral'' finite range scattering wave function (FRSW) [J. Chem. Phys. [bold 99], 1057 (1993)]. The FRSW method involves evaluation of the scattering matrix and its energy derivative, both of which are only parametrically dependent on energy. The energy independent matrices are determined from the discrete eigenvectors of the L[sup 2] Hamiltonian matrix [bold H], which is obtained in discrete variable representation, and an exact (analytical) eigenfunction of the asymptotic Hamiltonian operator [ital [cflx H]][sub 0]. Many long-lived ([gt]1 ps) resonances are identified for OH--Ar in [ital J]=3 with projections of [ital J] onto the intermolecular axis of [ital K]=0--3. The resonances are characterized with approximate bend and stretch quantum numbers based on the nodal structure of the wave functions. The predissociative states decay by Coriolis coupling to a lower [ital K] state and/or through mixing of OH rotor levels induced by the anisotropy of the interaction potential. States that predissociate by Coriolis coupling are identified by their [ital J]-dependent lifetimes and the OH product rotational levels accessed. The influence of potential anisotropy on the predissociative resonances is explored by changing the average intermolecular bond length and degree of intermolecular bending excitation. A comparison of the theoretically calculated resonances with those observed experimentally provides a guide for refinement of the adjusted semiempirical potential energy surface [J. Chem. Phys. [bold 98], 9320 (1993)] used in the computations.
- OSTI ID:
- 6601702
- Journal Information:
- Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 102:5; ISSN JCPSA6; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR MOMENTUM
ARGON COMPLEXES
ASYMPTOTIC SOLUTIONS
COMPLEXES
CORIOLIS FORCE
CORRELATIONS
DISSOCIATION
ENERGY DEPENDENCE
ENERGY LEVELS
EXCITED STATES
FREQUENCY MIXING
FUNCTIONS
HAMILTONIANS
HYDROXYL RADICALS
INTEGRALS
INTERMOLECULAR FORCES
LIFETIME
MATHEMATICAL OPERATORS
NUMERICAL SOLUTION
PREDISSOCIATION
QUANTUM OPERATORS
RADICALS
RESONANCE
ROTATIONAL STATES
SCATTERING
VAN DER WAALS FORCES
WAVE FUNCTIONS
YIELDS