Vibrational Corrections to Nuclear Magnetic Resonance Second Moments

Abstract

The effect of rapid nuclear motions on the observable second moments of nuclear-magnetic resonance-absorption lines is considered by the method of lattice harmonics. An explicit formula is given in terms of time-averaged values of lattice harmonics. In the case of lattice vibrations in a cubic solid with a cubic point group at the nuclear site, the observable correction to the rigid lattice second moment is zero up to and including the second order in the relative nuclear amplitudes of vibration. In general, only the anisotropic vibrations contribute in second order to the observable second moment.