Surprisal analysis of classical trajectory calculations of rotationally inelastic cross sections for the Ar--N/sub 2/ system; influence of the potential energy surface

Journal Article · Mon Nov 15 04:00:00 EST 1976 · J. Chem. Phys.; (United States)

OSTI ID:7147604

Pattengill, M D; Bernstein, R B

Rotationally inelastic Ar--N/sub 2/ scattering on two different empirical potential energy surfaces has been investigated by the classical trajectory method. For each potential surface, state-to-state rotational transition cross sections sigma/sub j//sub prime//sub j (E) have been calculated at five total energies E and several initial rotational quantum states j of the N/sub 2/. Results obtained from the two potentials differ significantly with respect to final rotational state distributions, but the total inelastic cross sections are very similar. Consideration of the moments of the rotational energy transfer leads to the conclusion that the potential surface of Kistemaker and de Vries is the preferred one to represent the Ar--N/sub 2/ interaction. A surprisal analysis of the computed cross sections has been carried out. At energies below approx. =3000 K, near-linear surprisal plots are obtained, as found earlier by Levine, Bernstein, Procaccia et al., thus confirming the exponential gap law of Polanyi, Ding, and Woodall for rotational relaxation. Complete cross section matrices (at a given E) can thereby be generated from a two-parameter surprisal fit of a single column of a sigma/sub j//sub prime//sub j matrix (or even from a classically derived first moment from the state j=0). As expected, the rotational surprisal parameter theta/sub R/ is essentially independent of j, but it shows a significant, positive E dependence and differs in magnitude for the two potentials. (AIP)

• Research Organization: Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506
• OSTI ID: 7147604
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 65:10; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
COLLISIONS
CRYOGENIC FLUIDS
ELEMENTS
ENERGY
ENERGY LEVELS
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
FLUIDS
INELASTIC SCATTERING
INTERMOLECULAR FORCES
MOLECULE COLLISIONS
NITROGEN
NONMETALS
POTENTIAL ENERGY
RARE GASES
ROTATIONAL STATES
SCATTERING