Overall, our computational results show that the extended amide III region is a promising target for extracting structural information from 2D-IR spectra. In particular, it can be expected that the cross-peaks between the classical amide III vibrations and the C α -H bending vibration show distinct differences for different structural motifs. Therefore, we propose to investigate the extended amide III region more closely experimentally. While this might be complicated by overlap of the extended amide III vibrations with solvent background, we hope that is work makes a compelling case for overcoming such experimental challenges.