The DI results agree with the EDR and allow us to investigate delocalization mechanisms in the two systems studied, as well as directly relate delocalization effects with FOs. First-neighbour π-DIs (i.e., between 1st and 2nd carbon atoms, etc.) throughout the chain reflect the expected bond structure for both cumulene (uniform double bonds) and polyyne (alternating single and . This can be explained by the fact that in this case, the DIs are taken over either two single bonds with one triple (≈ 0.02 electrons shared), or vice versa (≈ 0.12 electrons shared), as the delocalization between two triple bonds is expected to be much stronger than between two single bonds. Interestingly, though, the average of asymptotes for both -cumulene and polyyne third-neighbour π-DIs -are quite similar (0.07 vs 0.08 shared electrons), indicating that the same overall charge is delocalized over π bonds in both structures, meaning that it is a characteristic value for p orbitals in sp-hybridized carbon chains. For the free electron gas, any n-neighbour DI should be constant throughout the chain, implying that cumulene better fits this description, as in polyyne, the delocalization between the conjugated triple bonds becomes hindered by single bonds. Therefore, the differences in DIs explain larger amplitudes of FOs observed for the cumulene as compared to the polyyne chain of the same size.