Analyze the void space in the input structure using voronoi decomposition
    Calls Zeo++ for Voronoi decomposition.

    Args:
        structure: pymatgen.core.structure.Structure
        rad_dict (optional): Dictionary of radii of elements in structure.
            If not given, Zeo++ default values are used.
            Note: Zeo++ uses atomic radii of elements.
            For ionic structures, pass rad_dict with ionic radii
        probe_rad (optional): Sampling probe radius in Angstroms. Default is
            0.1 A

    Returns:
        voronoi nodes as pymatgen.core.structure.Strucutre within the
        unit cell defined by the lattice of input structure
        voronoi face centers as pymatgen.core.structure.Strucutre within the
        unit cell defined by the lattice of input structure

def get_voronoi_nodes(structure, rad_dict=None, probe_rad=0.1):
    """
    Analyze the void space in the input structure using voronoi decomposition
    Calls Zeo++ for Voronoi decomposition.

    Args:
        structure: pymatgen.core.structure.Structure
        rad_dict (optional): Dictionary of radii of elements in structure.
            If not given, Zeo++ default values are used.
            Note: Zeo++ uses atomic radii of elements.
            For ionic structures, pass rad_dict with ionic radii
        probe_rad (optional): Sampling probe radius in Angstroms. Default is
            0.1 A

    Returns:
        voronoi nodes as pymatgen.core.structure.Strucutre within the
        unit cell defined by the lattice of input structure
        voronoi face centers as pymatgen.core.structure.Strucutre within the
        unit cell defined by the lattice of input structure
    """

    with ScratchDir('.'):
        name = "temp_zeo1"
        zeo_inp_filename = name + ".cssr"
        ZeoCssr(structure).write_file(zeo_inp_filename)
        rad_file = None
        rad_flag = False

        if rad_dict:
            rad_file = name + ".rad"
            rad_flag = True
            with open(rad_file, 'w+') as fp:
                for el in rad_dict.keys():
                    fp.write("{} {}\n".format(el, rad_dict[el].real))

        atmnet = AtomNetwork.read_from_CSSR(
            zeo_inp_filename, rad_flag=rad_flag, rad_file=rad_file)
        vornet, vor_edge_centers, vor_face_centers = \
            atmnet.perform_voronoi_decomposition()
        vornet.analyze_writeto_XYZ(name, probe_rad, atmnet)
        voro_out_filename = name + '_voro.xyz'
        voro_node_mol = ZeoVoronoiXYZ.from_file(voro_out_filename).molecule

    species = ["X"] * len(voro_node_mol.sites)
    coords = []
    prop = []
    for site in voro_node_mol.sites:
        coords.append(list(site.coords))
        prop.append(site.properties['voronoi_radius'])

    lattice = Lattice.from_lengths_and_angles(
        structure.lattice.abc, structure.lattice.angles)
    vor_node_struct = Structure(
        lattice, species, coords, coords_are_cartesian=True,
        to_unit_cell=True, site_properties={"voronoi_radius": prop})

    # PMG-Zeo c<->a transformation for voronoi face centers
    rot_face_centers = [(center[1], center[2], center[0]) for center in
                        vor_face_centers]
    rot_edge_centers = [(center[1], center[2], center[0]) for center in
                        vor_edge_centers]

    species = ["X"] * len(rot_face_centers)
    prop = [0.0] * len(rot_face_centers)  # Vor radius not evaluated for fc
    vor_facecenter_struct = Structure(
        lattice, species, rot_face_centers, coords_are_cartesian=True,
        to_unit_cell=True, site_properties={"voronoi_radius": prop})

    species = ["X"] * len(rot_edge_centers)
    prop = [0.0] * len(rot_edge_centers)  # Vor radius not evaluated for fc
    vor_edgecenter_struct = Structure(
        lattice, species, rot_edge_centers, coords_are_cartesian=True,
        to_unit_cell=True, site_properties={"voronoi_radius": prop})

    return vor_node_struct, vor_edgecenter_struct, vor_facecenter_struct