Rotational excitation of symmetric top molecules by collisions with atoms: close coupling, coupled states, and effective potential calculations for NH/sub 3/--He. [Thermal energies]

Technical Report · Thu Jan 01 04:00:00 EST 1976

OSTI ID:7312274

Green, S

The formalism for describing rotational excitation in collisions between symmetric top rigid rotors and spherical atoms is presented both within the accurate quantum close-coupling framework and also the coupled states approximation of McGuire and Kouri and the effective potential approximation of Rabitz. Calculations are reported for thermal energy NH/sub 3/--He collisions, treating NH/sub 3/ as a rigid rotor and employing a uniform electron gas (Gordon--Kim) approximation for the intermolecular potential. Coupled states are found to be in nearly quantitative agreement with close-coupling results, while the effective-potential method is found to be at least qualitatively correct. Modifications necessary to treat the inversion motion in NH/sub 3/ are discussed. (auth)

• Research Organization: National Aeronautics and Space Administration, New York (USA). Goddard Inst. for Space Studies
• OSTI ID: 7312274
• Report Number(s): N-76-22001; NASA-TM-X-72994
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
AMMONIA
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
COLLISIONS
COUPLING
CRYOGENIC FLUIDS
ELEMENTS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
FLUIDS
HELIUM
HYDRIDES
HYDROGEN COMPOUNDS
INTERMOLECULAR FORCES
MOLECULE COLLISIONS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
RARE GASES
ROTATIONAL STATES