CTK File
CTK files have been retained because of the familiarity that many MedChem Studio users have with them, but they have been superseded by the XTK format. CTK files store the same information as XTK files, and within ADMET Predictor the two formats can be used interchangeably. However, note that while ADMET Predictor is able to open CTK files generated by MedChem Studio, the reverse is not true.
If you wish to export data from ADMET Predictor for use in MedChem Studio (as opposed to the MedChem Studio module in ADMET Predictor), you must use a structure format such as SDF or SMILES.
Three special CTK files are provided with ADMET Predictor. CoordinateGenerationTemplates.ctk contains template structures for use in MedChem Designer, while drugFragments_chemSpecific.ctk and drugFragments_skeletons.ctk are provided for use in R-group and scaffold replacement.