# Floquet.m

Floquet magic angle spinning context. Generates a Liouvillian super- operator and passes it on to the pulse sequence function, which sho- uld be supplied as a handle. Syntax:

answer=floquet(spin_system,pulse_sequence,parameters,assumptions)

where pulse sequence is a function handle to one of the pulse sequences located in the experiments directory, assumptions is a string that would be passed to assume.m when the Hamiltonian is built and parameters is a structure with the following subfields:

parameters.rate - spinning rate in Hz

parameters.axis - spinning axis, given as a normalized 3-element vector

parameters.spins - a cell array giving the spins that the pulse sequence involves, e.g. {'1H','13C'}

parameters.offset - a cell array giving transmitter off- sets in Hz on each of the spins listed in parameters.spins array

parameters.max_rank - maximum harmonic rank to retain in the solution (increase till conver- gence is achieved, approximately equal to the number of spinning si- debands in the spectrum)

parameters.grid - spherical grid file name. See grids directory in the kernel.

Additional subfields may be required by the pulse sequence. The parameters structure is passed to the pulse sequence with the following additional parameters set:

parameters.spc_dim - matrix dimension for the spatial dynamics subspace

parameters.spn_dim - matrix dimension for the spin dynamics subspace

This function returns the powder average of whatever it is that the pulse sequence returns.

Note: the choice of the rank depends on the spinning rate (the slower the spinning, the greater ranks are required). The rank is appro- ximately equal to the number of spinning sidebands.

Note: the state projector assumes a powder -- single crystal MAS is not currently supported.