The OpencanSARchem pipeline consists of five steps (Fig. ) outlined below, similar to canSARchem pipeline, with the key difference being in that desalting precedes tautomer canonicalization. The input to the OpencanSARchem workflow is in Simplified Molecular Input Line Entry System (SMILES) notation or in a Structure Data File (SDF). The "Structure Checker" step converts the input to an RDKit Mol object with "sanitize=True" option, which performs partial sanitization. Any failed conversion is followed with "sanitize=False" option to detect the chemistry problem(s) within the structure (e.g., AtomValenceException, KekulizeException, etc.). If practical, the workflow corrects the problem on the fly; otherwise, the incorrect or problematic molecular records are saved for manual curations. For example, processing ligands from the Protein Data Bank resulted in 0.001% of records requiring manual curation, and for ChEMBL 34, only a single failure from over 2 million records required intervention.