2D-IR spectroscopy for proteins is predominantly done within the amide I region (i.e., probing the coupled carbonyl stretching vibrations of the amide groups). Besides experimental considerations -most importantly the fact that the amide I vibrations show a particularly strong infrared intensity -this is facilitated by the availability of empirical exciton models 34 for the amide I vibrations. Such models can be used for efficiently predicting 2D-IR spectra in the amide I region. Conversely, the lack of such models beyond the amide I vibrations -and thus the inability of making reliable computational predictions -precludes the interpretation of 2D-IR spectra in other spectral regions and hampers the application of 2D-IR spectroscopy beyond the amide I region. Exceptions include the use of artificial amino acids or of specific functional groups as labels for 2D-IR spectroscopy. So far, only very few studies have explored 2D-IR spectroscopy using protein backbone vibrations beyond the amide I region. DeFlores et al. as well as Maekawa et al. investigated the cross peaks between the amide I and the amide II vibrations and demonstrated that these are highly sensitive to secondary structure. Despite some effort for parametrizing suitable exciton models, the interpretation of such experiments remains partly elusive.