# Singlerot.m

Fokker-Planck single angle spinning context. Generates a Liouvillian superoperator and passes it on to the pulse sequence function, which should be supplied as a handle.

## Contents

## Syntax

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

## Arguments

pulse_sequence - pulse sequence function handle. See the experiments directory for the list of pulse sequences that ship with Spinach. parameters.rate - spinning rate in Hz. Positive numbers for JEOL, negative for Varian and Bruker due to different rotation directions. 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.rframes - rotating frame specification, e.g. {{'13C',2},{'14N,3}} requests second order rotating frame transformation with respect to carbon-13 and third order rotating frame transformation with respect to nitrogen-14. When this option is used, the assumptions on the respective spins should be laboratory frame. parameters.grid - spherical grid file name. See grids directory in the kernel. parameters.sum_up - when set to 1 (default), returns the powder average. When set to 0, returns individual answers for each point in the powder as a cell array. parameters.* - additional subfields may be required by your pulse sequence - check its documentation page assumptions - context-specific assumptions ('nmr', 'epr', 'labframe', etc.) - see the pulse sequence header for information on this setting.

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

## Outputs

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

## Examples

The following example files in the *Spinach* example set make use of this context function:

**kinetics/mas_exchange_1.m** - chemical exchange unser magic angle spinning

**nmr_overtone/mas_glycine_1.m** - 14N MAS quadrupo9lar overtone spectrum

**nmr_solids/mas_powder_gly_fplanck.m** - glycine 13C MAS NMR spectrum

**nmr_solids/mas_powder_dip_fplanck.m** - MAS NMR on a pair of dipole coupled spins

**nmr_solids/mas_powder_csa_fplanck.m** - MAS NMR on a simple system with a CSA

## Notes

- Arbitrary order rotating frame transformation is supported, including infinite order. See rotframe.m for further information.
- Use 'single_crystal' powder grid for single crystal simulations.
- The function supports parallel processing via Matlab's Distributed Computing Toolbox - different system orientations are evaluated on different labs.

## See also

powder.m, liquid.m, roadmap.m, doublerot.m, crystal.m, imaging.m, gridfree.m, floquet.m

*Version 2.2, authors: Ilya Kuprov*