@article {337,
	title = {Rational reduction of periodic propagators for off-period observations},
	journal = {Journal of Magnetic Resonance},
	volume = {166},
	year = {2004},
	note = {J Magn Reson767TUTimes Cited:2Cited References Count:19},
	month = {Feb},
	pages = {174-181},
	abstract = {<p>Many common solid-state nuclear magnetic resonance problems take advantage of the periodicity of the underlying Hamiltonian to simplify the computation of an observation. Most of the time-domain methods used, however, require the time step between observations to be some integer or reciprocal-integer multiple of the period, thereby restricting the observation bandwidth. Calculations of off-period observations are usually reduced to brute force direct methods resulting in many demanding matrix multiplications. For large spin systems, the matrix multiplication becomes the limiting step. A simple method that can dramatically reduce the number of matrix multiplications required to calculate the time evolution when the observation time step is some rational fraction of the period of the Hamiltonian is presented. The algorithm implements two different optimization routines. One uses pattern matching and additional memory storage, while the other recursively generates the propagators via time shifting. The net result is a significant speed improvement for some types of time-domain calculations. (C) 2003 Published by Elsevier Inc.</p>
},
	keywords = {simulation},
	isbn = {1090-7807},
	doi = {Doi 10.1016/J.Jmr.2003.10.002},
	url = {<Go to ISI>://WOS:000188469400005},
	author = {Blanton, W. B. and Logan, J. W. and Pines, A.}
}
@article {347,
	title = {Rotary resonance recoupling for half-integer quadrupolar nuclei in solid-state nuclear magnetic resonance spectroscopy},
	journal = {Journal of Chemical Physics},
	volume = {117},
	year = {2002},
	note = {J Chem Phys599CVTimes Cited:22Cited References Count:53},
	month = {Oct 15},
	pages = {7024-7033},
	abstract = {<p>Investigations were made of rotary resonance recouplings (R-3) of chemical shift anisotropy (CSA), heteronuclear dipolar (HTD), and homonuclear dipolar (HMD) couplings involving half-integer quadrupolar nuclei under magic-angle sample spinning condition. Under rotary resonance conditions provided by a low amplitude rf field and a high spinning speed, the spectrum of the central transition coherence of half-integer quadrupolar nuclei shows recouplings of CSA, HTD, and HMD interactions that depend on the ratio of the rf field to the spinning speed. These new properties can be used to extract electronic and structural information about the sample that are otherwise difficult to extract in the presence of a dominant quadrupolar interaction. An average Hamiltonian theory is used to explain the recoupling properties of various interactions. Experimental implementations of the R-3 are demonstrated on model compounds with spin-3/2 systems. (C) 2002 American Institute of Physics.</p>
},
	keywords = {polarization},
	isbn = {0021-9606},
	doi = {Doi 10.1063/1.1506907},
	url = {<Go to ISI>://WOS:000178317300016},
	author = {Wi, S. and Logan, J. W. and Sakellariou, D. and Walls, J. D. and Pines, A.}
}
