Intermolecular Potential and Second Virial Coefficient of the Water-Hydrogen Complex

Published

January 1, 2004

Author(s)

M P. Hodges, R J. Wheatley, G K. Schenter, Allan H. Harvey

Abstract

We construct a rigid-body (5-dimensional) potential-energy surface for the water-hydrogen complex using scaled perturbation theory (SPT). An analytic fit of this surface is obtained, and using this, two minima are found: the global miniumum has C_2v symmetry, with the hydrogen molecule action as a proton donor to the oxygen atom on water, where the OH bond and H₂ are in a T-shaped configuration. The SPT global minimum is bound by 1097 muE_h(E_h=4.359744 X 10^-18 J). Our best estimate of the binding energy, from a complete basis set exrtapolation of coupled cluster calculations, is 107.1 muE_h. The fitted surface is used to calculate the second cross virial coefficient over a wide temperature range (100-3000 K). Three complementary methods are used to quantify quantum statistical mechanical effects that become significant at low temperatures. We compare our results with experimental data, which are available over a moderate temperature range (230-700 K). Generally, good agreement is found, but the experimental data are subject to larger uncertainties.

Citation

Journal of Chemical Physics

Volume

120

Issue

No. 2

Pub Type

Journals

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Keywords

aqueous systems, hydrogen, intermolecular potential, second virial coefficient, water

Citation

Hodges, M. , Wheatley, R. , Schenter, G. and Harvey, A. (2004), Intermolecular Potential and Second Virial Coefficient of the Water-Hydrogen Complex, Journal of Chemical Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=831920 (Accessed October 13, 2025)