Benchmark calculations are required to evaluate the accuracy of our approach for calculating harmonic IR and Raman spectra of solute-solvent systems. To this end, we investigated the pseudo-translational and pseudo-rotational contributions to all normal modes and the convergence with respect to basis set size, system size, and configurational sample size. In the following, the 30 normal modes of acetone have been labeled in descending order from 1 (highest frequency) to 30 (lowest frequency).