Close coupling calculations on rotational excitation and inversion of NH[sub 3] by collisions with Ar

Journal Article · Sun Nov 01 04:00:00 EST 1992 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.463704· OSTI ID:6916714

van der Sanden, G C.M.; Wormer, P E.S.; van der Avoird, A ^[1]; Schleipen, J; ter Meulen, J J ^[2]

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1. Institute of Theoretical Chemistry, University of Nijmegen, Toernooiveld, 6525 ED Nijmegen (Netherlands)
2. Department of Molecular and Laser Physics, University of Nijmegen, Toernooiveld, 6525 ED Nijmegen (Netherlands)

State-to-state total cross sections for rotational excitation and inversion of NH[sub 3] by collisions with Ar have been calculated within the accurate close coupling framework. The inversion motion in NH[sub 3] was included both via a delta function model and by taking the inversion coordinate explicitly into account. We used an [ital ab] [ital initio] potential and a potential in which one term in the angular expansion of the [ital ab] [ital initio] potential is scaled in order to reproduce spectroscopic data. At the energies of these calculations the delta function model is found to be in nearly quantitative agreement with the exact'' inversion results. Comparison with experiment shows the original [ital ab] [ital initio] potential to be better than the scaled one. The state-to-state cross sections for ortho-NH[sub 3] are in general accord with the measurements. For para-NH[sub 3] the agreement is good also, but the relative magnitudes of the cross sections for transitions to the [plus minus] inversion states of the same rotational level are not reproduced correctly for all levels.

• OSTI ID: 6916714
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 97:9; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664300* -- Atomic & Molecular Physics-- Collision Phenomena-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
AMMONIA
ARGON
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
COLLISIONS
CROSS SECTIONS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FLUIDS
GASES
HYDRIDES
HYDROGEN COMPOUNDS
MOLECULE COLLISIONS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
RARE GASES
ROTATIONAL STATES
SCALING LAWS
TOTAL CROSS SECTIONS