VIBRATIONAL LINE SHIFTS OF HYDROGEN HALIDES IN A RARE-GAS ENVIRONMENT- HF DF AND HCL/DCL IN AR MATRICES AND CLUSTERS/

Vibrational frequency shifts of fundamental and higher excitations of HF/DF and HCl/DCl in a rare gas environment are calculated using vibra tionally dependent atom-molecule potentials. For both octahedral and i cosahedral geometry corresponding to a substitutional site in fcc matr ices and in medium sized clusters the shift is monitored for an increa sing number of up to ten solvation shells. Saturation is reached for t he fifth octahedral and for the third icosahedral shell. Good agreemen t with matrix experiments is found for the shift of the fundamental fr equency, while the potential used here does not extrapolate well for t he higher excitations of HCl.