Conclusions:

1. Lemniscular (Möbius) phyrins may be good calibrants of DFT Methods (relatively easy synthesis, crystallography and NMR)
2. The built-in twists may attenuate π overlaps and hence reduce π-distortivity.
3. Bond delocalization may persist beyond 38π-electrons, and possibly beyond 72!
4. Planar annulenes probably show a lower alternation onset at between 22-26 π-electrons (greater π distortivity).
5. B3LYP is probably the best (2nd rung) DFT method for predicting the aromatic edge of chaos.
   • 2004: We propose that synthesis and accurate structure determination of a more comprehensive set of (molecules) could serve as a novel type of reference library which could serve as the basis for developing even better hybridisations of density functional and other (correlated) methods. (DOI: 10.1039/b312724a)
   B2GP-B2PLYP/TZVPP 5th rung needs calibration to 38π-electrons and beyond.
6. BUT: still a discrepancy between the predicted structure/NMR and measured NMR for [18]annulene.