PISEMA Experiments: 2D PISEMA experiment to correlate X chemical shifts with 1H-X dipolar couplings, frequency switched Lee-Goldburg during 1H-15N dipolar evolution (pisema.av) 2D PISEMA experiment 2D pulse sequence to correlate X chemical shifts with 1H-X dipolar couplings and using ramped contact during FSLG period (pisemaramp.av) PISEMA experiment based on the Magic-Sandwich Decoupling in the indirect dimension (sammy.av)