Hnco.m

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Phase-sensitive HNCO pulse sequence from

            http://dx.doi.org/10.1016/0022-2364(90)90333-5

using the bidirectional propagation method described in

             http://dx.doi.org/10.1016/j.jmr.2014.04.002

The sequence is hard-wired to work on 1H,13C,15N proteins. Syntax:

              fid=hnco(spin_system,parameters,H,R,K)

where H is the hamiltonian commutation superoperator, R is the re- relaxation superoperator and K is the chemical kinetics superope- rator. The following parameters are required:

     parameters.npoints     - a vector of three integers giving the
                              number of points in the three temporal
                              dimensions, ordered as [t1 t2 t3].
     parameters.sweep       - a vector of three real numbers giving
                              the sweep widths in the three frequen-
                              cy dimensions, ordered as [f1 f2 f3].
     parameters.tau         - the three delays required for the ope-
                              ration of the sequence (see the paper)
                              in seconds. Reasonable values are
                              [2.25e-3, 14e-3, 4e-3]
     parameters.f1_decouple - logical switch controlling proton de-
                              coupling during the T1 period.

Dimensions: F1 is N, F2 is CO, F3 is H.

Note: spin labels must be set to PDB atom IDs ('CA', 'HA', etc.) in sys.labels for this sequence to work properly.