A three-dimensional potential energy surface and infrared spectra for the Ar–OCS van der Waals complex

The first three-dimensional potential energy surface (PES) of the Ar–OCS complex is developed at the coupled cluster single and double with noniterative treatment of triple excitations [CCSD(T)] level with a large basis set plus midpoint bond functions. Two vibrationally adiabatic potentials at both the ground and the first vibrational v3 excited states are generated by averaging the three-dimensional potential over the Q3 coordinate. The predicted infrared spectra are in excellent agreement with the available experimental data, which again testifies the accuracy of the new potentials.