A classical canonical Monte Carlo computation for Ar-54-HF between 1 and 50 K is performed. The results demonstrate that the Ar-HF exchange is significantly different in Ar-54-HF compared to what has been found for Ar-12-HF. The HF molecule in Ar-54-HF does not leave the center of the cluster prior to the melting onset within the walk length used here. Additionally, the melting of the cluster is affected significantly by the presence of the chromophore.