A review presents the anal. expressions of the first- and second-order quadrupole interactions for a static crystal, and for a crystal rotating at variable or magic angle. It also provides mathematica notebooks for calcg. the anal. expressions of existing interactions. Nested phase cycling in MQMAS sequences applied to half-integer quadrupole spins is described. The basic two- and three-pulse MQMAS sequences are also described, with emphasis on the detn. of phase cycles for slecting the desired coherence pathways and reciprocally all coherence transfer pathways selected by a phase cycle. [on SciFinder(R)]