{ital Ab initio} study of the van der Waals interaction of NH(X{sup 3}{Sigma}{sup {minus}}) with Ar({sup 1}S)
- 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, Vol. 108, Issue 8; Other Information: PBD: Feb 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
ab initio Study of the O2 (X3E-g) + Ar (1S) van der waals interaction
Ab initio potential energy surface for the Ar({sup 1}S)+OH(X{sup 2}{pi}) interaction and bound rovibrational states