Content:

- Columns from BUSTER (refine.mtz)
- Using BUSTER MTZ file in Coot
- Comparing column names for different refinement programs

A BUSTER output MTZ file (usually named `refine.mtz`) generally contains twenty-four columns:

Column names |
Origin |
Description |
Scale |

H,K,L | Reflection indices. | N/A | |

FP,SIGFP (or similar) | input | Observed data (amplitude and sigma). The column names will be identical to the column names of the input data. |
Observational (unmodified from input). |

FreeR_flag (or similar) | input | Flag indicating which reflections are in the free set. Copied from input if present, otherwise created afresh. | N/A |

FC,PHIC | BUSTER | Calculated structure factors (amplitude and phase) for the complete model, containing atomic model, bulk-solvent and (if specified) the missing atom model. |
Absolute |

2FOFCWT,PH2FOFCWT | BUSTER | Coefficients for the electron-density map defined as 2*m*Fo-D*Fc*. |
Absolute |

FOFCWT,PHFOFCWT | BUSTER | Coefficients for the electron-density difference map defined as m*Fo-D*Fc. |
Absolute |

FOM | BUSTER | Figure of merit: m. |
N/A |

HLA,HLB,HLC,HLD | BUSTER | Hendrickson-Lattman coefficients of the BUSTER phase probability distribution. | N/A |

FCTR,PHICTR | BUSTER | Coefficients for the centroid electron density map. | Absolute |

FOFRGSLV,PHFOFRGSLV | BUSTER | Coefficients for the electron-density map defined as 2*m*Fo-D*Fc without the contribution of the missing atom model to FC. Usually there is no missing atom model defined for a BUSTER refinement, in which case these columns will be identical to the FOFCWT,PHFOFCWT columns. | Absolute |

FOSC,SIGFOSC | BUSTER | Observed data (see FP,SIGFP above) scaled to FC. | Absolute |

FX | BUSTER | Expectation of the amplitude of the complex-valued model structure factor. | Absolute |

For visualising the typical set of maps (2Fo-Fc and difference map), eg. Coot could be started with

% coot --pdb refine.pdb --auto refine.mtz

and it will pick the correct columns (2FOFCWT/PH2FOFCWT and FOFCWT/PHFOFCWT) automatically.

To simplify switching between refinement programs (or following documentation written for one refinement program), here are some column names compared. Please note that some programs allow the user to use any name they want for the output columns - we are only listing the default names in the table below.

Explanation |
BUSTER |
REFMAC |
Remark |

2Fo-Fc map coefficients | 2FOFCWT PH2FOFCWT | FWT PHWT | |

Fo-Fc (difference map) coefficients | FOFCWT PHFOFCWT | DELFWT PHDELWT | |

Figure of merit | FOM | FOM | |

Model structure factor | FC PHIC | FC_ALL PHIC_ALL | Atomic and bulk-solvent model; BUSTER will also contain the contribution from the (optionally declared ) missing atoms. |