A cross-hydrogen bond ^4hJ_N,N coupling constant in N-H....O=C-N system of 0.13 Hz. ( 00JACS3206) from a 2D HN(N)-TOCSY experiment.

Cross-hydrogen bond ^3hJ_P,N and ^2hJ_P,H coupling constants in N-H....O-P spin systems in a protein-nucleotide complex using a{31P] spin-echo difference 15N CT-TROSY and 3D HNPO experiments ( 00JACS5883) and a protein using similar TROSY type experiments ( 00JACS9289).