$ gemmi merge -h
Usage:
  gemmi merge [options] INPUT_FILE OUTPUT_FILE
  gemmi merge --stats [options] UNMERGED_FILE
  gemmi merge --compare [options] UNMERGED_FILE MERGED_FILE
  gemmi merge --compare [options] MMCIF_FILE_WITH_BOTH
Options:
  -h, --help             Print usage and exit.
  -V, --version          Print version and exit.
  -v, --verbose          Verbose output.
  --anom                 Output/compare I(+) and I(-) instead of IMEAN.
  --no-sysabs            Remove systematic absences.
  --batch-cell           Use cell parameters from MTZ batch headers.
  --nobs                 Add MTZ column NOBS with the number of merged
                         reflections.
  --input-block=NAME     Input mmCIF block name (default: first unmerged).
  -b NAME, --block=NAME  Output mmCIF block name: data_NAME (default: merged).
  --stats[=N]            Print data metrics in N resol. shells (default: 10).
                         Add U (e.g. =10U or =U) for unweighted metrics.
                         Add X for XDS-like weighted metrics (details in docs).
                         Add s or e for different binning (more in docs).
  --compare              Compare unmerged and merged data (no output file).
  --print-all            Print all compared reflections.

The input file can be SF-mmCIF with _diffrn_refln, MTZ or XDS_ASCII.HKL.
The output file can be either SF-mmCIF or MTZ.
