NMR in incommensurate systems: non-local effects

Abstract
The NMR lineshape and spin-lattice relaxation rate in incommensurate systems are evaluated for the case where, in addition to local contributions to the NMR frequency, non-local contributions also have to be taken into account. The case of a static wave as well as the case of a floating modulation wave are treated and the theoretical results are compared with experimental data.