rotor_stack.m

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

Syntax

[L,rotor_phases]=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 the notes on rotation conventions for the basic definitions of rotations in Spinach.

See also

singlerot.m, doublerot.m, powder.m

Version 2.1, authors: Ilya Kuprov