Low energy vibrational relaxation of the diatomic molecule I/sub 2/ (B) by collision with He

Journal Article · Sat May 01 04:00:00 EDT 1982 · J. Chem. Phys.; (United States)

OSTI ID:5651487

Villarreal, P; Delgado-Barrio, G; Mareca, P

A quantum mechanical study of the collision I/sub 2/(B /sup 3/Pi/sub 0/ , n = 1, j = 0)+He..-->..I/sub 2/(B /sup 3/Pi/sub 0/ , n = 0, j')+He is reported here. The initial relative kinetic energies are lower than 0.7 cm/sup -1/. The I/sub 2/(B) diatom is approximated by a harmonic oscillator, while the atom--diatom interaction is described by two atom--atom Morse type potentials. The close-coupling equations for nuclear motion, within the body-fixed frame, have been solved numerically. The partial vibrational relaxation cross sections, corresponding to the J = 0,1,2 values of the total angular momentum, have been obtained as a function of energy. When several rotational channels in the n = 1 vibrational level are introduced in the calculation, resonances do appear with lifetimes of the order of several ps. These resonances enhance the efficiency of the collision. Their positions, at very low energies, cause the dependence of the mean cross section with increasing temperature to be a fast decreasing function, in agreement with experimental results.

• Research Organization: Instituto de Estructura de la Materia, C.S.I.C., Serrano 119, Madrid-6, Spain
• OSTI ID: 5651487
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 76:9; 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
COLLISIONS
CROSS SECTIONS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FLUIDS
GASES
HALOGENS
HELIUM
IODINE
MOLECULE COLLISIONS
NONMETALS
RARE GASES
RELAXATION
VIBRATIONAL STATES