Magic Angle Spinning and Truncated Field Concept in NMR

Figure 5

(a) Graphical representation of angular dependence of dipolar coupling strength described by the 2^nd Legendre polynomial. Coloured in red and in orange are effective local magnetic fields produced by and spins respectively, (b) certain arbitrarily chosen pair of spins under magic angle spinning conditions, and (c) frame of reference for two interacting spins.