NMR is a vital tool for measuring the dynamics of biological macromolecules in solution. The chemical exchange observed is often divided into slow or intermediate exchange. Slow exchange affects principally the z magnetizations of the system, and is observed in modified spin-lattice relaxation experiments.
Intermediate exchange gives rise to broadening and coalescence in the spectrum itself.
This broadened spectrum is often considered as a whole, but we have shown that it is better to regard it as a sum of transitions, with a generalized picture of the transition probability.