$ gemmi mondiff -h
Usage:
  gemmi mondiff [options] FILE1 FILE2
Options:
  -h, --help         Print usage and exit.
  -V, --version      Print version and exit.
  -v, --verbose      Verbose output.

Minimal reported differences:
  --bond=DELTA       difference in distance value (default: 0.01).
  --bond-esd=DELTA   difference in distance esd (default: 0.1).
  --angle=DELTA      difference in angle value (default: 0.1).
  --angle-esd=DELTA  difference in angle esd (default: 1.0).
  --rel=SIGMA         abs(value difference) / esd > SIGMA (default: 0.0).