Rotor stack.m

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Returns a rotor stack of Liouvillians or Hamiltonians. The stack is needed for the traditional style calculation of MAS dynamics.

Syntax

    L=rotor_stack(spin_system,parameters,assumptions)

Arguments

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

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

  parameters.spins    - a cell array giving the spins that 
                        the offsets refer to, e.g. {'1H','13C'}

  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.orientation - the orientation of the spin system
                           at rotor phase zero, a vector of 
                           three Euler angles in radians.

  parameters.masframe    - the frame in which the rotations 
                           are applied. The possibilities are:

           'magnet' - the initial orientation in the lab frame
                      (three-angle powder grids will be required)

           'rotor'  - the initial orientation in the rotor frame
                      (two-angle powder grids will be required)

  assumptions       - assumption set to be used in generating the
                      Hamiltonian, see assume.m

Outputs

      L   - a cell array of Hamiltonian or Liouvillian matrices,
            one for each tick of the rotor.

      rotor_phases - rotor phases at each tick, radians

Notes

Relaxation and kinetics are not included.

See also

singlerot.m, doublerot.m, powder.m


Version 2.1, authors: Ilya Kuprov