Multichannel quantum defect analysis of two-state couplings in diatomic molecules

Journal Article · Thu Mar 15 04:00:00 EST 1984 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.447046· OSTI ID:5142190

Mies, F H; Julienne, P S

A multichannel quantum defect analysis (MCQDA) for non-Coulomb potentials is applied to two-channel coupling in diatomic molecules. Given the exact 2 x 2 scattering matrix S(E) obtained at a single energy above the dissociation threshold E>0, we can extract an analytic, energy-insensitive 2 x 2 matrix Y(E) which can be extrapolated across thresholds and yield a complete description of predissociating molecules. The predicted widths, shifts, and line shapes obtained from MCQDA are in quantitative agreement with the exact numerical results and confirm the remarkable simplicity that can be achieved in describing diatomic systems near dissociation limits. The analysis is equally applicable to either adiabatic avoided crossings or diabatic curve crossings. The validity of MCQDA is independent of coupling strength and can quantitatively describe strongly overlapped predissociating resonance states. The application of MCQDA to the bound state spectrum, when both channels are closed, is discussed.

• Research Organization: Molecular Spectroscopy Division, National Bureau of Standards, Washington, DC 20234
• OSTI ID: 5142190
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 80:6; 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-ATOM COLLISIONS
BOUND STATE
COLLISIONS
DISSOCIATION
INELASTIC SCATTERING
MECHANICS
MOLECULES
PREDISSOCIATION
QUANTUM MECHANICS
SCATTERING