docs: def morgan_sim(mol1, mol2, radius=2, digit=3):
      """Calculate morgan fingerprint similarity by using RDKit
      radius=2 roughly equivalent to ECFP4
      """
      rdmol1 = to_rdmol(mol1)
      rdmol2 = to_rdmol(mol2)
      fp1 = AllChem.GetMorganFingerprint(rdmol1, radius)
      fp2 = AllChem.GetMorganFingerprint(rdmol2, radius)
      return round(DataStructs.DiceSimilarity(fp1, fp2), digit)