The rovibrational energy levels of van der Waals complexes Ar-HF and Ar-DF have been obtained by using a numerical calculation based on the discrete variable representation (DVR) method. These calculated energy levels are in good agreement with the observed levels. The higher-order angular anisotropy and the vibrational depdndence of the intermolecular potential energy surface have been investigated by comparision between the calculated and observed values. The isotopic shift rule of the van der Waals stretching and bending vibrational frequency of Ar-DF relative to Ar-HF system has been obtained from DVR calculation of these sysem. The blue shift effects of the van der Waals vibrational frequencies with v appears when HF stretch vibrational excitation is increased.

Key words: ARGON, HYDROGEN FLUORIDE, VIBRATIONAL STATE, POTENTIAL ENERGY SURFACES