{ital Ab initio} study of the O{sub 2}(X{sup 3}{Sigma}{sub g}{sup {minus}})+Ar({sup 1}S) van der Waals interaction

Journal Article · Thu May 01 04:00:00 EDT 1997 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.473798· OSTI ID:565267

Cybulski, S M ^[1]; Kendall, R A ^[2]; Chalasinski, G ^[3]; Severson, M W; Szczesniak, M M ^[4]

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1. Department of Chemistry, Miami University, Oxford, Ohio 45056 (United States)
2. High Performance Computational Chemistry Group, Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352-0999 (United States)
3. Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warszawa (Poland)
4. Department of Chemistry, Oakland University, Rochester, Michigan 48309 (United States)

A potential energy surface for the Ar({sup 1}S)+O{sub 2}(X{sup 3}{Sigma}{sub g}{sup {minus}}) interaction is calculated using the supermolecular unrestricted Mo/ller{endash}Plesset (UMP) perturbation theory and analyzed via the perturbation theory of intermolecular forces. The global minimum occurs for the T-shaped geometry, around 6.7a{sub 0}. Our UMP4 estimate of the well depth of the global minimum is D{sub e}=117cm{sup {minus}1} and the related ground state dissociation energy obtained by diffusion Monte Carlo calculations is 88cm{sup {minus}1}. These values are expected to be accurate to within a few percent. The potential energy surface also reveals a local minimum for the collinear geometry at ca{approximately}7.6a{sub 0}. The well depth for the secondary minimum at the UMP4 level is estimated at D{sub e}=104cm{sup {minus}1}. The minima are separated by a barrier of 23cm{sup {minus}1}. The global minimum is determined by the minimum in the exchange repulsion in the direction perpendicular to the O{endash}O bond. The secondary, linear minimum is enhanced by a slight flattening of the electron density near the ends of the interoxygen axis. {copyright} {ital 1997 American Institute of Physics.}

• Research Organization: Pacific Northwest National Laboratory
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 565267
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 18 Vol. 106; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ARGON
ATOM-MOLECULE COLLISIONS
CHEMICAL REACTIONS
COMPLEXES
DISSOCIATION ENERGY
GROUND STATES
INTERACTIONS
INTERATOMIC FORCES
MONTE CARLO METHOD
OXYGEN
PERTURBATION THEORY
POTENTIAL ENERGY
POTENTIALS
VAN DER WAALS FORCES