The QI maps of θ = 180 • are both similar to and different from those of θ = 0 • . The similarity is in the color structure, red terms remain red in both cases and similarly blue terms remain blue, the differences come from the relative magnitudes of the terms (here represented by the darkness of the color) and this gives a visual appearance of a significant difference. At E = 0eV, the HOMO and LUMO constructively interfere as seen by the dark red squares in Figure . There are destructive interference terms between these frontier orbitals and the HOMO-1 and LUMO+1, however, the constructive QI terms between the HOMO and the LUMO, and the noninterfering terms do not cancel with the destructive interference terms. Thus, the transmission at E = 0eV does not go to zero. For the QI maps calculated at E = ±2.23eV, the transport is dominated by a single orbital with a single non-interfering term from either the HOMO or LUMO (the energetically proximate orbital in each case. Interestingly, this is the closest approximation we see to the single-orbital/single-level tunnelling model that has sometimes been invoked to explain the differences in transport properties between different molecules.