MOMENTS OF THE POWER SPECTRA OF DIPOLAR INTERACTION BETWEEN SPIN-1 2 NUCLEI/

The evaluation of the second moment from dipolar-broadened lines leads to a higher degree of reproducibility if the power spectrum is used, Very small deviations in the baseline far away from the center of the line caused by small phase differences are an important reason for poo r reproducibility of second moments of absorption-mode spectra. This p aper shows that, in the case of dipolar interaction of spins I = 1/2, the second moment of the power spectrum depends on geometrical paramet ers in the same way as the real-part second moment does. However, ther e is no trivial general relation between the moments of absorption and power spectra. (C) 1996 Academic Press, Inc.