CommunicationQuadrupolar transfer pathways

A set of graphical conventions called quadrupolar transfer pathways is proposed to describe a wide range of experiments designed for the study of quadrupolar nuclei with spin quantum numbers I = 1, 3/2, 2, 5/2, etc. These pathways, which inter alea allow one to appreciate the distinction between quadrupolar and Zeeman echoes, represent a generalization of the well-known coherence transfer pathways. Quadrupolar transfer pathways not merely distinguish coherences with different orders −2I ⩽ p ⩽ +2I, but allow one to follow the fate of coherences associated with single transitions that have the same coherence order p=mIr-mIs but can be distinguished by a satellite order q=(mIr)2-(mIs)2.