In Figure we illustrate the QI maps for θ = 49 • and θ = 50 • at E = ±0.38eV (the energies of the interference features for θ = 49 • ) and at E = 0eV. The most striking feature of all these maps is how similar they are. In both cases, the map at E = 0eV is more symmetric in terms of the contributions from occupied and virtual orbitals, while the maps at E = ±0.38eV show some asymmetry, however this asymmetry is not very pronounced. While there are undoubtedly quantitative differences between the two dihedral angles, it is not possible to see this from the plots. In all cases, the similar color structure that was seen for θ = 180 • and θ = 0 • is retained, and the similarity is more readily apparent as the quantitative differences are reduced. Figure and Figure paint a different orbital picture of destructive interference in butane from what was seen in benzene. Firstly, in butane more orbitals are involved (4) compared with benzene (2) despite the significantly larger HOMO-LUMO gap (over 4eV for butane versus 2eV for benzene). Secondly, the change from a system with clear destructive interference effects(θ = 0 -49 • ) to a system with suppressed transmission(θ = 50 -180 • ) results from a change in the magnitude of the various orbital contributions rather than any contributions changing sign. Together, these two differences mean that the QI maps are not as simple to interpret for saturated systems. This is not an indication of any failure of the QI map, but simply an indication that the interference effects in saturated systems are more subtle as the system can vary from continuously from being dominated by constructive to destructive interference without any dramatic change in the orbital character.