Proton-decoupled 31P and 14N NMR spectra characterizing bicellar (B), lamellar (L) or isotropic (I) structures and freeze-fracture electron microscopy pictures (from top to bottom) of DMPC liposomes (h = 80%), DMPC/DCPC systems (X = 78%; h = 80%, 100 mM KCl) and TBBPC/DCPC systems (X = 78%; h = 80%, 100 mM NaCl). At the bottom right, sketches of bicellar discs oriented with their normal parallel (B∥) or perpendicular (B⊥) to the magnetic field direction B0. Adapted from [19,45].