Figure 20.

Calculated 2D-IR spectra for the OD stretch of HOD in liquid H₂O, respectively, in bulk water and in the hydration shell of subtilisin Carlsberg in hexane at different hydration levels, for waiting times ranging from 0 to 2 ps. The horizontal and vertical axes correspond to the excitation and detection frequencies, respectively, in cm^–1. Each spectrum is normalized with respect to the positive peak height. The black lines show the center line slope⁸⁰ on a 150 cm^–1 wide interval centered on the positive peak.