Find and return all :class:`Molecule` s in :class:`MolecularSystem`.

        This function populates :attr:`MolecularSystem.molecules` with
        :class:`Molecule` s.

        Parameters
        ----------
        rebuild : :class:`bool`
            If True, run first the :func:`rebuild_system()`. (default=False)

        Returns
        -------
        None : :class:`NoneType`

def make_modular(self, rebuild=False):
        """
        Find and return all :class:`Molecule` s in :class:`MolecularSystem`.

        This function populates :attr:`MolecularSystem.molecules` with
        :class:`Molecule` s.

        Parameters
        ----------
        rebuild : :class:`bool`
            If True, run first the :func:`rebuild_system()`. (default=False)

        Returns
        -------
        None : :class:`NoneType`

        """
        if rebuild is True:
            supercell_333 = create_supercell(self.system)
        else:
            supercell_333 = None
        dis = discrete_molecules(self.system, rebuild=supercell_333)
        self.no_of_discrete_molecules = len(dis)
        self.molecules = {}
        for i in range(len(dis)):
            self.molecules[i] = Molecule(dis[i], self.system_id, i)