However, vibrational spectroscopy does not provide direct structural information. Therefore, the ability to extract structural and dynamical information from vibrational spectra, in particular from 2D-IR spectra, crucially depends on the availability of computational tools . Only by predicting vibrational spectra for (models of) biomolecular structures and by carefully comparing predicted and experimental spectra it becomes possible to establish relationships between the underlying molecular structure and spectral features (for examples, see Refs. , and to extract structural and dynamical information from experimental 2D-IR spectra .