Fig. 6: Models of Fddd phase and its alternatives.
From: A case of antiferrochirality in a liquid crystal phase of counter-rotating staircases
a, b Layers at different z-elevation for (a) IC3/n and (b) FCN16/FO16. c, d Snapshots of MD-annealed atomistic models (xy layer; purple: aromatic, gray/white: aliphatic). e, f Comparison of the network model of Fddd phase in poly(styrene-b-isoprene) (yellow rods) with the model of IC3/n. Arrows indicate a helical sense of both columns and network. g, h Two dimers of FO16/FCN16 on neighboring columns in g represented by quadrupoles in h, where geometrical parameters are also defined. i, j Side and top views of (i) co-rotating and (j) counter-rotating ribbons. k Minimum-energy configurations on a 2D-hexagonal lattice; k1 two left- and two right-handed columns in a 2 × 2 supercell, equivalent to the Fddd structure here observed experimentally; k2 three left- and one right-handed column in a 2 × 2 supercell; k3 four right-handed columns in a 2 × 2 supercell; it turns out that vertical shifting of the second row of columns relative to the first does not change the system energy; (k4) two left- and one right-handed column in a \(\sqrt{3}\times \sqrt{3}\) supercell. The orientation of right-handed columns can be random, which does not affect the system energy (cf. structure in ref. 27). In k1–k4 right- (left-)handed columns are shades of blue (red).
