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)

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; this is the direction
                        around which the rotor is turning

  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 rotor harmonic rank to retain
                        in the solution (increase till conver-
                        gence is achieved, a good guess value
                        is the number of spinning sidebands
                        expected 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. Two-angle
                        grids should be used in Liouville
                        space and three-angle grids in Hil-
                        bert space.

  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 the pulse sequence - check its do-
                        cumentation 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 follo-
wing 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.

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