# Appendix E: experiment parameters

From Spinach Documentation Wiki

This section summarises the common sibfields of the parameters data structure used by Spinach kernel contexts and experiment simulations. This data structure must be passed to context (e.g. powder.m) and pulse sequence (e.g. noesy.m) functions. Individual functions may also have their own case-specific parameters, always check the manual page for the function that you use.

Subfield | Data type | Notes |
---|---|---|

parameters.sweep | A vector of reals. | Sweep width in each dimension of the spectrum (Hz). |

parameters.npoints | A vector of integers. | Number of points in each dimension of the output data array. |

parameters.rho0 | A state vector or a density matrix. | Initial state for the simulation. |

parameters.coil | A state vector or a density matrix. | Detection state for the simulation. |

parameters.decouple | A cell array of spin specifications, e.g. {'13C','15N'}. | Spins that must be decoupled analytically during the simulation. |

parameters.spins | A cell array of spin specifications, e.g. {'13C','15N'}. | Spins that are to be assigned to each instrument channel during the simulation. |

parameters.J | A vector of reals. | The values of J-couplings that should be used for coherence transfer stages of NMR pulse sequences. |

parameters.spc_dim | integer number | The dimension of the spatial sub-problem in a Fokker-Planck space. This parameter sould normally be set by the kernel context function and passed on to the pulse sequence. |

parameters.spn_dim | integer number | The dimension of the spin sub-problem in a Fokker-Planck space. This parameter sould normally be set by the kernel context function and passed on to the pulse sequence. |

parameters.rf_pwr | a vector of real numbers | radiofrequency irradiation powers on each channel |

parameters.rf_dur | a vector of real numbers | radiofrequency irradiation durations on each channel |

parameters.rf_frq | a vector of real numbers | radiofrequency irradiation frequencies on each channel |

parameters.rf_phi | a vector of real numbers | radiofrequency irradiation initial phases on each channel |

parameters.rf_rnk | a vector of real numbers | radiofrequency irradiation Floquet or Fokker-Planck rank on each channel |

parameters.rf_opr | a cell array of sparse matrices | radiofrequency irradiation operators on each channel |

parameters.angle | a vector of reals | pulse flip angles for those experiments that require them |

parameters.mw_pwr | a vector of real numbers | microwave irradiation powers on each channel |

parameters.mw_dur | a vector of real numbers | microwave irradiation durations on each channel |

parameters.mw_frq | a vector of real numbers | microwave irradiation frequencies on each channel |

parameters.mw_phi | a vector of real numbers | microwave irradiation initial phases on each channel |

parameters.mw_rnk | a vector of real numbers | microwave irradiation Floquet or Fokker-Planck rank on each channel |

parameters.mw_opr | a cell array of sparse matrices | microwave irradiation operators on each channel |

parameters.rho_eq | a state vector or a denisty matrix | equilibrium state for the experiments that require it |

parameters.rlx | a sparse matrix | relaxation superoperator for the experiments that require it separately |

parameters.rframes | a cell array of the following shape: {{'E',2},{'1H',1}} with the first element indicating the spins and the second the order of the rotating frame transformation | numerical rotating frame transformation specification |

parameters.theory | a character string | theory specification for experiments that can be computed using several methods |

parameters.rate | real numbers | spinning rate for single rotation solid state NMR experiments |

parameters.axis | three-element real vector | rotor axis for single rotation solid state NMR experiments |

parameters.grid | character string with a file name | spherical averaging grid for solid state experiments |

parameters.rank | positive integer | Floquet or Fokker-Planck rank for single rotation solid state NMR experiments |

parameters.rate_inner | real number | inner rotor spinning rate for double rotation solid state NMR experiments |

parameters.rate_outer | real number | outer rotor spinning rate for double rotation solid state NMR experiments |

parameters.axis_inner | three-element real vector | inner rotor axis for double rotation solid state NMR experiments |

parameters.axis_outer | three-element real vector | outer rotor axis for double rotation solid state NMR experiments |

parameters.rank_inner | positive integer | Floquet or Fokker-Planck rank for the inner rotor in double rotation solid state NMR experiments |

parameters.rank_outer | positive integer | Floquet or Fokker-Planck rank for the outer rotor in double rotation solid state NMR experiments |