MOPAC can accept any of the following formats: Cartesian, MOPAC internal coordinates, a mixture of Cartesian and MOPAC internal coordinates, and Gaussian internal coordinates. Both MOPAC and Gaussian Z-matrices can also contain dummy atoms. If the `0SCF` option is requested, the geometry defined on input will be printed in MOPAC Z-matrix format, along with other optional formats.

The type(s) of geometry printed at the end of a 0SCF calculation depend only on the keywords XYZ, INT, AIGOUT, and NOXYZ. The geometry printed is independent of the type of input geometry, and therefore makes a convenient conversion mechanism.

If `XYZ` is present, all dummy atoms are removed and the internal coordinate definition remade. All symmetry relations are lost if `XYZ` is used.

If `NOXYZ` is present, Cartesian coordinates will not be printed. If `AIGOUT` is present, a data set using Gaussian Z-matrix format is printed.

Note: Only if the keyword SYMMETRY is present in a MOPAC internal coordinate geometry, or two or more internal coordinates in a Gaussian Z-matrix have the same symbolic will symmetry be present in the MOPAC or Gaussian geometries output.