Cp contact hard.m

Cross-polarization NMR experiment in the rotating frame. Syntax:

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

Parameters:

    parameters.irr_powers - a vector containing the values
                            of the RF power on each channel

    parameters.irr_opers  - a cell array of spin operators
                            corresponding to the irradiation
                            on each RF channel

    parameters.exc_opers  - excitation operator for the exci-
                            tation pulse (pi/2).

    parameters.rho0       - initial state

    parameters.coil       - detection state