Calculation of coherence pathway selection and cogwheel cycles.

The selection of proper coherence pathways is a very important aspect of the design of NMR pulse sequences. This article describes a C++ program for the calculation of coherence pathway selection via phase cycles, including a module to calculate cogwheel cycles. Cogwheel phase cycles shorter than the original ones [M.H. Levitt et al., J. Magn. Reson. 155 (2002) 300] are derived and experimentally tested for the MQMAS experiment for 3/2 spins. Some other cogwheel cycles are derived for the MQNQMAS, the STMAS experiment, and a PFG diffusion pulse sequence. This program is publicly available through our website http://www.nyu.edu/projects/jerschow with additional documentation and examples.