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.

Syntax

    [answer,sph_grid]=singlerot(spin_system,pulse_sequence,...
                                  parameters,assumptions)

Parameters

  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     - powder averaging grid

  parameters.needs    - a cell array of character strings spe-
                        cifying additional requirements that
                        the sequence has:

                         'iso_eq' - thermal equilibrium state
                         of the isotropic Hamiltonian will be
                         placed into parameters.rho0

  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

answer - powder average, or a cell array, of whatever the pulse sequence returns

sph_grid - spherical grid used in the calculation

Notes

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

See also

Kernel contexts

Solid state NMR experiments

Version 2.8, authors: Ilya Kuprov