QuacPac can read and write a variety of molecular file formats. The file format is automatically interpreted from the filename suffix.
| File type | Extension |
| SMILES | .smi .ism .can .smi.gz .ism.gz .can.gz |
| SDF | .sdf .mol .sdf.gz .mol.gz |
| SKC | .skc .skc.gz |
| CDK | .cdk .cdk.gz |
| MOL2 | .mol2 .mol2.gz |
| PDB | .pdb .ent .pdb.gz .ent.gz |
| MacroModel | .mmod .mmod.gz |
| OEBinary v2 | .oeb .oeb.gz |
| Old OEBinary | .bin |
Old OEBinary format can be read but not written by QuacPac.
Gzipped OEBinary version 2 (.oeb.gz) is the recommended output format.
QuacPac is also capable of piping formatted input and output.
The simple "-" can be used in place of a file name to indicate
std::cin or std::cout with the default SMILES format.
prompt> (quacpac application) -in - -out -
This execution will run QuacPac with std::cin as the
input with SMILES format. It will also open std::cout with
SMILES format as output. However, the use of "-" does not allow control of
the file format.
To control the format of std::cin and std::cout one may use
the file extensions without a preceeding filename.
prompt> (quacpac application) -in .ism -out .oeb.gz
This executes QuacPac with the input from std::cin formated
in isomeric SMILES and the output sent to std::cout in gzipped OEBinary
version 2 format.