Development and optimization of multipulse propagators: Applications to homonuclear spin decoupling in solids

We introduce a new class of semi-windowless pulse sequences for homonuclear decoupling in solids. The development and optimization of the multiple-pulse sequences relies on the definition of quality factors that reflect the proximity of the created effective Hamiltonian to the desired Hamiltonian. A quality factor based on the average Hamiltonian theory gives a global view of the existing solutions. However, the sequences were optimized using a quality factor based on exact numerical solutions of the Liouville von Neumann equation. The new decoupling sequences are stable over a wide range of coupling constants and chemical shifts.