This module reads and writes MOPAC 6 input files. It can handle both internal
coordinates and cartesian coordinates. It also extracts molecules from summary
files, defined as those files that match /SUMMARY OF/ in the third line.
Perhaps a future version will extract additional information such as the energy
and dipole from the summary file.
This module registers the mop format with Chemistry::Mol. For detection
purposes, it assumes that filenames ending in .mop or .zt have the Mopac
format, as well as files whose first line matches /am1|pm3|mndo|mdg|pdg/i
(this may change in the future).
When the module reads an input file into $mol, it puts the keywords (usually
the first line of the file) in $mol->attr(mopac/keywords), the comments
(usually everything else on the first three lines) in
$mol->attr(mopac/comments) and $mol->name, and the internal coordinates for
each atom in $atom->internal_coords.
When writing, the kind of coordinates used depend on the coords option, as
shown in the SYNOPSIS. Internal coordinates are used by default. If the
molecule has no internal coordinates defined or the rebuild option is set,
the build_zmat function from Chemistry::InternalCoords::Builder is used to
renumber the atoms and build the Z-matrix from scratch.