Mh. Levitt et M. Eden, Numerical simulation of periodic nuclear magnetic resonance problems: fastcalculation of carousel averages, MOLEC PHYS, 95(5), 1998, pp. 879-890
Many nuclear magnetic resonance (NMR) problems involve spin evolution in th
e presence of a periodic Hamiltonian. In many cases, calculation of the spi
n response requires a 'carousel average', meaning a summation of NMR signal
s over all cyclic permutations of the perturbation. Symmetry theorems are d
erived which in many cases allow this carousel average to be performed with
minimal computational effort. This has implications for the computation of
NMR spectra under asynchronous decoupling sequences, and for the computati
on of powder NMR spectra in the presence of sample rotation. Calculated mag
ic-angle spinning powder spectra of L-[C-13(3)] alanine are compared with e
xperimental results.