Morphing the He-OCS intermolecular potential

Abstract

The application of morphing procedure to the potential energy surface of He-OCS was analyzed. The potential was calculated at a grid defined in prolate spheroidal coordinates and an aug-cc-pVTZ basis set was used for coupled cluster calculations at the CCSD(T) level. The potential was then morphed by energy and the intermolecular distance in a coordinate-dependent way, and the function parameters for morphing were determined by a least-squares fit to the experimental data. Results show that the morphing procedure increased the well depth more at the sulfur end than at the oxygen end, and the anisotropically morphed potential reproduced the measured rotational transitions to within 1 MHz.