For the Jansen model (Fig. ), there is a very good correlation between predicted and reference local-mode frequencies for the four polyalanine models. For the α-helix, there is a systematic shift of ca. 9 cm -1 , while for the other three models, the ME is below 3.2 cm -1 . In all four cases, the RMSD is comparable and amounts to 3.8-7.7 cm -1 , and the coefficient of determination is larger than 0.9 in all four cases. We note that the color coding in the figure nicely highlights that local modes in similar positions in the polypeptide chain appear at similar frequencies. For instance, for the α-helix and the 3 10 -helix, the local-mode frequencies for the peptide close to both ends of the chain are shifted to higher wavenumbers, while those in the middle of the chain appear at lower wavenumbers. For the β-hairpin, the local-modes that lie within the turn are shifted to particularly high wavenumbers.