HCL-RARE GAS VANDERWAALS DIMERS TRAPPED IN RARE-GAS MATRIX - INTERPRETATION OF THE VIBRATION-ORIENTATION SPECTRUM

Two semiempirical potentials are used to interpret the vibration-orientation spectrum of the hydrogen chloride-RG* dimers trapped in RG matrices (RG*, RG = Ar, Kr, Xe). The geometries of these dimers are calculated by including matrix relaxation and compared to those observed in the gas phase. It is shown that dimers in matrices can have radial and angular configurations very different from those reported in the gas phase, which have been used to fit potential parameters. The main features of the experimental spectrum of the trapped dimers are satisfactorily interpreted on the basis of one or the other potential. But none can lead to a universal interpretation of the infrared spectra of all the dimers. Arguments are developed on the main causes of discrepancies.