We construct a rigid-body (five-dimensional) potential-energy surface for the water-nitrogen complex using the systematic intermolecular potential extrapolation routine (SIMPER). The intermolecular potential is then extrapolated to the limit of a complete basis set. An analytic fit of this surface is obtained, and, using this, the global minimum is found. The minimum is located in an arrangement in which N2 is near the H atom of H2O, almost collinear with the OH bond. Our best estimate of the binding energy is 441 cm-1. The extrapolated potential is then used to calculate the second cross virial coefficient over a wide temperature range (100-3000 K). Generally good agreement with experiment is found, but the experimental data are subject to larger uncertainties.
Citation: Journal of Chemical Physics
Pub Type: Journals
intermolecular potential, mixtures, nitrogen, virial coefficient, water