Molecular orbitals (MOs) have long been an essential tool in the toolbox of chemists. While they are not physical observables, they have nonetheless been used to develop intuition for and predict physical properties. Recently, the ⇡-MOs of some linear carbon molecules have received increased attention due to their helical topology. An example of such a proclaimed helical ⇡-orbital is shown in Figure . This is the HOMO of S -1,5-Me- [4]cumulene and it is clearly shaped like a helix. In appropriately substituted molecules, these MOs occur due to mixing of the otherwise orthogonal ⇡-systems as the symmetry of the molecule is reduced. This helical nature of the ⇡-system is a fundamental consequence of the molecular symmetry and is evident when an appropriate Hückel model is made for the symmetryadapted MOs as shown in Figure . Even at the Hückel level of theory, it is clear that the MOs are imperfect helices as the angular steps along the molecular axis differ in magnitude. The helicality of the electronic structure is thus ill-defined as even the most helical cases may not be perfect cylindrical helices. In the following, we will use the term "helicality" to refer to how close an MO is to a cylindrical helix. The helicality of an MO is large if it is close to a perfect cylindrical helix.