def uniform_labels(self, mol1, mol2):
"""
Pair the geometrically equivalent atoms of the molecules.
Calculate RMSD on all possible isomorphism mappings and return mapping
with the least RMSD
Args:
mol1: First molecule. OpenBabel OBMol or pymatgen Molecule object.
mol2: Second molecule. OpenBabel OBMol or pymatgen Molecule object.
Returns:
(list1, list2) if uniform atom order is found. list1 and list2
are for mol1 and mol2, respectively. Their length equal
to the number of atoms. They represents the uniform atom order
of the two molecules. The value of each element is the original
atom index in mol1 or mol2 of the current atom in uniform atom
order.
(None, None) if unform atom is not available.
"""
obmol1 = BabelMolAdaptor(mol1).openbabel_mol
obmol2 = BabelMolAdaptor(mol2).openbabel_mol
h1 = self.get_molecule_hash(obmol1)
h2 = self.get_molecule_hash(obmol2)
if h1 != h2:
return None, None
query = ob.CompileMoleculeQuery(obmol1)
isomapper = ob.OBIsomorphismMapper.GetInstance(query)
isomorph = ob.vvpairUIntUInt()
isomapper.MapAll(obmol2, isomorph)
sorted_isomorph = [sorted(x, key=lambda morp: morp[0])
for x in isomorph]
label2_list = tuple([tuple([p[1] + 1 for p in x])
for x in sorted_isomorph])
vmol1 = obmol1
aligner = ob.OBAlign(True, False)
aligner.SetRefMol(vmol1)
least_rmsd = float("Inf")
best_label2 = None
label1 = list(range(1, obmol1.NumAtoms() + 1))
# noinspection PyProtectedMember
elements1 = InchiMolAtomMapper._get_elements(vmol1, label1)
for label2 in label2_list:
# noinspection PyProtectedMember
elements2 = InchiMolAtomMapper._get_elements(obmol2, label2)
if elements1 != elements2:
continue
vmol2 = ob.OBMol()
for i in label2:
vmol2.AddAtom(obmol2.GetAtom(i))
aligner.SetTargetMol(vmol2)
aligner.Align()
rmsd = aligner.GetRMSD()
if rmsd < least_rmsd:
least_rmsd = rmsd
best_label2 = copy.copy(label2)
return label1, best_label2
def _graph_isomorphism(self, obmol1, obmol2):
""" Graph isomorphism from openbabel.
"sympairs" is similar to rdkit's output,
in which symmetric atoms get the same index.
"""
# fundamental openbabel graph isomorphism
query = ob.CompileMoleculeQuery(obmol1)
mapper = ob.OBIsomorphismMapper.GetInstance(query)
isomorphs = ob.vvpairUIntUInt()
mapper.MapAll(obmol2, isomorphs)
# sympairs
n = obmol1.NumAtoms()
sympairs_atob = [set() for _ in range(n)]
sympairs_btoa = [set() for _ in range(n)]
for isomorph in isomorphs:
for pair in isomorph:
i = pair[0]
j = pair[1]
sympairs_atob[i].add(j)
sympairs_btoa[j].add(i)
return isomorphs, sympairs_atob, sympairs_btoa