def compute_rotsym(self, threshold=<NUM_LIT>*angstrom):
<EOL>graph = MolecularGraph.from_geometry(self, scaling=<NUM_LIT>)<EOL>try:<EOL><INDENT>return compute_rotsym(self, graph, threshold)<EOL><DEDENT>except ValueError:<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>
Compute the rotational symmetry number.

           Optional argument:
            | ``threshold``  --  only when a rotation results in an rmsd below the given
                                 threshold, the rotation is considered to transform the
                                 molecule onto itself.