For the Tokmakoff model, the plots in Fig. indicate hardly any remaining correlation between the local-mode vibrational frequencies predicted by the map and the reference values provided by quantum-chemical calculation. For all six considered structures, the RMSD amounts to around 20 cm -1 , which is larger to the RMSD of the reference localmode frequencies themselves. Consequently, R 2 is below zero for all test cases. While for the isolated polypeptide models, all three considered vibrational maps were in reasonable agreement with the reference values obtained from quantum-chemical calculation, the picture changes dramatically when looking at solvated polypeptides. Here, we find that for the solvated polypeptides, there is hardly any correlation between the local-mode frequencies predicted by the vibrational maps and the reference values extracted from quantum-chemical calculations. This is particularly striking, as in both the quantum-chemical calculations and when evaluating the vibrational maps, the solvent molecules are consistently treated as classical point charges.