$ gemmi map2sf -h
Usage:
  gemmi map2sf [options] MAP_FILE OUTPUT_FILE COL_F COL_PH

Writes map coefficients (amplitude and phase) of a map to OUTPUT_FILE.
The output is MTZ if it has mtz extension, otherwise it is mmCIF.

Options:
  -h, --help       Print usage and exit.
  -V, --version    Print version and exit.
  -v, --verbose    Verbose output.
  -b, --base=PATH  Add new columns to the data from this file.
  --section=NAME   Add new columns to this MTZ dataset or CIF block.
  --dmin=D_MIN     Resolution limit.
  --ftype=TYPE     MTZ amplitude column type (default: F).
  --phitype=TYPE   MTZ phase column type (default: P).