{ital Ab initio} study of the van der Waals interaction of NH(X{sup 3}{Sigma}{sup {minus}}) with Ar({sup 1}S)

Journal Article · Sun Feb 01 04:00:00 EST 1998 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.475737· OSTI ID:615222

Kendall, R.A. Bukowski, R. ^[1]

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1. High Performance Computational Chemistry Group, Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington99352-0999 (United States); Department of Chemistry, University of Warsaw, Pasteura 1, 02-093Warszawa (Poland)

The potential energy surface for the Ar({sup 1}S)+NH(X{sup 3}{Sigma}{sup {minus}}) interaction is calculated using the supermolecular unrestricted Mo/ller{endash}Plesset (UMP) perturbation theory approach and analyzed via the perturbation theory of intermolecular forces. The global minimum occurs for the approximate T-shaped geometry with Ar skewed toward the H atom at about {Theta}=67{degree} and R=6.75a{sub 0}. Our UMP4 estimate of the well depth of the global minimum is D{sub e}=100.3cm{sup {minus}1} and the related ground state dissociation energy obtained by rigid-body diffusion quantum Monte Carlo calculations (RBDQMC) is D{sub 0}=71.5{plus_minus}0.1cm{sup {minus}1}. These values are expected to be accurate to within a few percent. The potential energy surface also features a wide plateau in the proximity of Ar-N-H collinear geometry, at ca. 7.0a{sub 0}. RBDQMC calculations reveal nearly a free rotation of the NH subunit in the complex. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 615222
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 8 Vol. 108; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ARGON
ATOM-MOLECULE COLLISIONS
DISSOCIATION ENERGY
ELECTRONIC STRUCTURE
MOLECULAR CLUSTERS
MONTE CARLO METHOD
NITROGEN HYDRIDES
PERTURBATION THEORY
QUANTUM MECHANICS
VAN DER WAALS FORCES