Universal scaling of potential energy functions describing intermolecular interactions. II. The halide-water and alkali metal-water interactions

Journal Article · Thu Aug 14 00:00:00 EDT 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4891820· OSTI ID:1164202

Werhahn, Jasper C. ^[1]; Akase, Dai ^[2]; Xantheas, Sotiris S. ^[3]

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1. Physik-Department E11, Technische Universität München, James-Franck-Strasse, D-85748 Garching, Germany
2. Center for Quantum Life Sciences and Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
3. Physical Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K1-83, Richland, Washington 99352, USA

The scaled versions of the newly introduced [S. S. Xantheas and J. C. Werhahn, J. Chem. Phys.141, 064117 (2014)] generalized forms of some popular potential energy functions (PEFs) describing intermolecular interactions – Mie, Lennard-Jones, Morse, and Buckingham exponential-6 – have been used to fit the ab initio relaxed approach paths and fixed approach paths for the halide-water, X^-(H₂O), X = F, Cl, Br, I, and alkali metal-water, M⁺(H₂O), M = Li, Na, K, Rb, Cs, interactions. The generalized forms of those PEFs have an additional parameter with respect to the original forms and produce fits to the ab initio data that are between one and two orders of magnitude better in the χ² than the original PEFs. They were found to describe both the long-range, minimum and repulsive wall of the respective potential energy surfaces quite accurately. Overall the 4-parameter extended Morse (eM) and generalized Buckingham exponential-6 (gBe-6) potentials were found to best fit the ab initio data for these two classes of ion-water interactions. Finally, the fitted values of the parameter of the (eM) and (gBe-6) PEFs that control the repulsive wall of the potential correlate remarkably well with the ionic radii of the halide and alkali metal ions.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1164202
• Report Number(s): PNNL-SA-78240; JCPSA6; KC0301020
• Journal Information: Journal of Chemical Physics, Vol. 141, Issue 6; ISSN 0021-9606
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English