The remaining two test cases, the 1GPB 3 10 -helix and Trpzip2, feature a large variety of amino acids in their protein chains. For both polypeptides, the local-mode frequencies are spread over a larger range compared to the polyalanine models. While the correlation between predicted and reference local-mode frequencies becomes worse, it still remains reasonable. For both models, there is a systematic shift of ca. 10-12 cm -1 , and the RMSD amounts to 10.6 cm -1 for 1GPB and to 18.1 cm -1 for Trpzip2. While for 1GPB, R 2 is still as large as 0.88, it drops to only 0.65 for Trpzip2.