A potential energy surface for He–OCS that agrees with experimental rotational spectra to within 1 MHz is presented. The potential was first calculated at a grid defined in prolate spheroidal coordinates, which give stabler interpolations than Jacobi coordinates. Coupled cluster calculations at the CCSD(T) level were carried out with an aug-cc-pVTZ basis set. The potential was then morphed, a procedure that scales the energy and the intermolecular distance in a coordinate-dependent way. The parameters of the function used for morphing were determined by a least-squares fit to the experimental data. The global minimum of the recommended potential, at is deeper than the unscaled potential of Higgins and Klemperer [J. Chem. Phys. 110, 1383 (1999)]. The morphing procedure increases the well depth by more at the sulfur end than at the oxygen end.
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Research Article| September 15 2001
Morphing the He–OCS intermolecular potential
Joanna M. M. Howson;
Joanna M. M. Howson, Jeremy M. Hutson; Morphing the He–OCS intermolecular potential. J. Chem. Phys. 15 September 2001; 115 (11): 5059–5065. https://doi.org/10.1063/1.1394940
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