Additional DFT geometry optimizations were performed on experimental crystal structures of the [n]helicene compounds, taken from the Cambridge Structural Database, in cases where a matching crystal structure was not generated by the quasi-random search. These were enantiopure structures of [7]helicene and [9]helicene (IMEJIW with Z ′ = 2 and QU-JNEQ with Z ′ = 3) and racemic structures of [5]helicene (DBPHEN03 with Z ′ = 2 and DBPHEN04 with Z ′ = 3). For the intergrowth structure of [6]helicene, the crystal structure was taken from Ref. 26.