2-D Rg-ACETYLENE INTERMOLECULAR POTENTIAL SURFACES FROM HIGH RESOLUTION NEAR INFRARED SPECTROSCOPY

Abstract

High resolution near infrared spectra have been obtained for both the Ar- and Ne-acetylene complexes. For Ar-acetylene, we have observed combination bands associated with the intermolecular bending mode, which are directly sensitive to the anisotropic part of the potential. In the case of Ne-acetylene, the spectrum shows clear evidence for free rotation of the acetylene sub-unit within the complex. Model HFD potentials have been constructed for both systems. The repulsive part of the potential is based upon a large number of high level SCF calculations, which include ghost orbital corrections, while the contribution from dispersion interactions is included empirically, being adjusted to fit the experimental spectra. The spectra are calculated using the collocation procedure, reported by Peet and $Yang^{1}$for Ar-HCI.