For the dephasing time, which influences the peak broadening, we chose T 2 = 2 ps for all calculations as this is a time scale often found in amide I vibrations. For the waiting time t 2 we used no time delay (i.e., S(ω 3 , t 2 = 0, ω 1 )). Our code for simulating 2D IR spectra is written using Python 3 and makes use of Numpy. All spectra are plotted using Matplotlib. A data set containing coordinates of all considered molecular structure, output data from the harmonic vibrational frequency calculations, the localization of normal modes and the anharmonic L-VSCF/L-VCI calculation as well as Python code and Jupyter notebooks that can be used for the calculation of 2D-IR spectra from this data and for generating the plots presented here is available at Ref. 107.