For full details of models see: www.kingsbury.id.au/scsd_model/dipyridyldicarbazole A recent article by Rickhaus and coworkers discusses the effect that a saddle-shaped macrocycle has on a directed self-assembly and uses the example of substituted dipyridyldicarbazoles macrocycles developed by Müllen's group (Fig. ). The saddle shape can be termed B1u distortion in SCSD; of 25.8 Å for Co II (tBu4dpdc) and 26.8 Å for H2(tBu4dpdc) from the crystallographic determinations previously reported (EGICAC and EGICEG). Other out-of-plane distortions (Au, B2g, B3g) hold small, non-zero values.