def create_molecular_graph(selected_nodes, parent=None):
molecule = create_molecule(selected_nodes, parent)
atom_indexes = dict((atom,i) for i,atom in enumerate(molecule.atoms))
bonds = list(
bond for bond in yield_bonds(selected_nodes)
if bond.children[0].target in atom_indexes and
bond.children[1].target in atom_indexes
)
pairs = [(
atom_indexes[bond.children[0].target],
atom_indexes[bond.children[1].target],
) for bond in bonds]
graph = MolecularGraph(pairs, molecule.numbers)
graph.bonds = bonds
graph.molecule = molecule
return graph
