Fig. 1.
Illustrations of relationships between RDC internuclei vector AB and an arbitrary molecular frame (a) and the alignment tensor frame (b). A protein molecule, carrying spin nuclei A and B, is represented using an ellipsoid. B0 is the external field. Θ is the instantaneous angle between the internuclei vector AB and B0. βx,y,z specify the projection angles of B0 onto each axis of a molecular frame. Polar angle θ; and azimuth angle ϕ are spherical coordinates of the vector AB in the alignment tensor frame