We calculate the transmission of Au-molecule-Au junctions for the 1181 selected structures. Briefly, junctions are created by placing the molecule between four-atom Au pyramids placed on 5 × 5 Au(111) surfaces. These junction structures are relaxed with the Au atoms kept fixed, then the transmission is calculated using DFT and the NEGF approach as implemented in ASE and GPAW. As in the wide-band calculations, we use the PBE functional and DZP basis set for all atoms, except for Au where a DZ basis set is applied. The transmission calculations using wide-band and Au electrodes are performed at a similar level theory, but the two types of electrodes differ. In Figure , the junction structures and transmissions for Si222 are shown for the two setups. Each wide-band electrode is depicted as a hydrogen molecule; it corresponds to a one-dimensional periodic chain of hydrogen atoms as detailed in supporting information part I. The Au-electrode is depicted as an Au-pyramid. Naturally, the electronic coupling of the electrodes into the sulfur atoms is quite different depending on whether it is through a hydrogen 1s orbital or an Au 6s orbital. In Figure it is notable that the transmission resonances are narrower using the wide-band electrodes, and consequently the transmission is generally lower. This is the consequence of the overlap between a hydrogen 1s and sulfur 3p orbital being smaller than that of Au 6s and sulfur 3p. This difference also seems to affect the sharpness of antiresonances in the transmission, which are less sharp in the Au calculation; we hypothesize this is the result of the diffuse Au orbitals coupling into multiple orbitals on sulfur and neighboring orbitals. While the transmission properties are generally preserved, we note that the antiresonance energy in Si222 changes by approximately half an eV. This again emphasizes that it is not straightforward to find one simple selection criterion to lowering the number of conformations we screen. Ideally the transmission should be qualitatively similar to that found with the computationally expensive Au-electrodes. Plotting the full data-set of the wide-band transmission as a histogram in Figure , it is clear that there are many structures with very low transmission, i.e. around 10 -6 and lower. Comparing the two data-sets with the wide-band and Au electrodes directly in Figure , there are notable differences as we alluded to in the previous section. Almost every junction has lower transmission at the Fermi energy (T(E F )) with wide-band electrodes. For the majority, the difference is fairly systematic. However, for a significant number of junctions the transmission at the Fermi energy is several orders of magnitude lower with wide-band electrodes, and these are cases where there is a sharp antiresonance near the Fermi energy. We do not find cases where the transmission with Au electrodes becomes extremely low. This is not an error in the wide-band transmission, it is just a different junction corresponding to an experiment that cannot easily be realized -one with hydrogen atoms as electrodes. Consequently, there is promise for other realistic electrode types, or different types of experiments, where destructive interference phenomena might be even more pronounced than with Au-electrodes. We find it informative to also look at the lowest transmission in the range 1.5 eV above and below the Fermi energy (T min ), looking for a sharp antiresonance within the HOMO-LUMO gap. Shown as a histogram in Figure , it is clear that there are now two subclasses of molecules. A notable fraction of molecules have lower transmission than at the Fermi energy; these are the ones with a sharp antiresonance in the transmission. Again, as listed in Table , Si222 performs very well among the top insulating molecules and ranks as no. 65 out of the 771 molecules of its class. Whether looking at the transmission at the Fermi energy or in a broader energy range, it is clear that though Si222 is an exceptional insulator, it is not a particularly special molecule within its class.