Difference spectra resulting after irradiation of the OH-stretch of H₂O for the three 20:1 mixtures and two pure pASW samples with different scaling factors. (a) Bandstrength of the OH-stretch of H₂O. (b) Bandstrength of the libration mode of H₂O. (c) Fluence of the FEL irradiation. (d) Combination of the libration mode bandstrength and the fluence. (e) Unscaled difference spectra. The darker solid lines in all the graphs are smoothed versions of the lighter traces in the background.