Two-dimensional NMR techniques which sep. the chem. shift and heteronuclear dipolar interactions were applied to samples spinning at the magic angle. Because of the inhomogeneous nature of the 2 interactions, rotational echoes were obsd. in the time domain of each dimension. The corresponding Fourier transforms yield rotational sideband spectra which provide information on the principal values and relative orientations of the shift and dipolar tensors, and from the latter, internuclear distances may be calcd. The techniques therefore provide a means for obtaining structural data, for example, 13C-1H and 15N-1H distances, in powder samples. [on SciFinder (R)]