We start by assessing the parent allene molecule in quasi-D 2 symmetry where only the three rotation axes are preserved. In D 2 symmetry the HOMOs and LUMOs are helical and the four transition densities arising from the direct MO excitations are shown in Figure . Products of MOs of the same helicity give a helical transition density that retains the helicity (P or M). Accordingly, these have notable electric and magnetic transition dipole moments. ⃗ µ is aligned along the z-axis of the molecule (the allenic axis). ⃗ m has a non-zero component along the z-axis and a larger compo-nent pointing in-between the two allenic planes, which results in an 80 o angle between the two transition dipole vectors. As illustrated in Figure , the direction of ⃗ m is in accordance with the right-hand rule considering the helicity of the transition density. The big off-axis component of ⃗ m comes from the linear charge displacement that is characteristic for ππ * transitions; thus the helix pitch is big and the charge does not rotate perfectly around the allenic axis. Only the z-component ( ⃗ m z ) aligns with ⃗ µ (equation 1), which is pointing along the allenic axis. To provide a sense of an upper-bound for the rotatory strength of substituted allenes, we can calculate R for this transition density that is associated to the MO transitions. The z-component of ⃗ m is parallel to ⃗ µ for π P → π * P giving positive R and anti-parallel for