Influence of the molecule continuum on inelastic vibrational energy transfer in atom--molecule collisions

Journal Article · Fri Aug 15 04:00:00 EDT 1980 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.440306· OSTI ID:5190050

Scherzinger, A L; Secrest, D

A study is made of the vibrational energy transfer in atom--diatomic molecule collisions for molecules with a dissociative continuum. The collision energy is kept below the dissociation limit. Comparisons are made of calculations performed using only the discrete molecular basis set, not including continuum functions, with exact calculations. A collinear model is used in these calculations in which the molecule is taken to be a Morse oscillator. It is found that for molecules with a shallow well, such as van der Waals molecules, the discrete molecular basis set never leads to converged scattering cross sections. For strongly bound molecules at low collision energies, the transitions among the lower states of the molecule are accurately described by only the discrete oscillator states, but at high collision energies or for states higher up in the well, the transition probabilities are often in error by more than a factor of 2. This is seen even when the calculation has appeared to converge with the discrete basis set. Errors due to the neglect of the continuum are not limited to transitions among states near to the continuum.

• Research Organization: School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801
• OSTI ID: 5190050
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 73:4; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
CALCULATION METHODS
COLLISIONS
DISSOCIATION
ENERGY LEVELS
ENERGY TRANSFER
EXCITED STATES
HARMONIC OSCILLATORS
INELASTIC SCATTERING
MOLECULE COLLISIONS
MORSE POTENTIAL
POTENTIALS
SCATTERING
VIBRATIONAL STATES