file.write(('{} monomers were merged into the alphabet because they have the same PDB ids (ligand / CCD), '
                        'but different structures (e.g., different stereochemistry or bond order):\n'
                        '  PDB-CCD ID\tPDB-CCD SMILES\tRESID SMILES\n'
                        '  {}\n\n').format(
                len(same_pdb_ids), '\n  '.join(sorted('\t'.join(n) for n in same_pdb_ids))))