A phase-sensitive ge-2D NOESY experiment incorporating a water flip-back pulse during the mixing time and the WATERGATE scheme, load the parameter set defined for the ge-2D NOESY experiment using WATERGATE, by typing rpar NOESYGPPH19SW all and getprosol, and change the pulse program to noesyfpgpphwg.

The only different parameters to be modified are:

• The water-selective 90 pulse (the water flip-back pulse) applied during the mixing time must be specified by p29 applied at a sp11 power level and with a spnam11 shape. phcor3 is the phase difference between this shaped pulse and a hard pulse.
• The water-selective 90 pulses of the WATERGATE block must be specified by p11 applied at a sp1 power level and with a spnam1 shape. phcor5 is the phase difference between this shaped pulse and a hard pulse.
• Gradients must be optimized to gpz1=50 (purgue gradient during the mixing time) and gpz2=30 (WATERGATE gradients).

Perform data acquisition and data processing as described in the original experiment.