Fig. 2: Crystal structure of R- and S-SEA-Si.
From: Molecular orbital breaking in photo-mediated organosilicon Schiff base ferroelectric crystals

a Molecular structures of R- and S-SEA-Si. b Packing pattern of R- and S-SEA-Si, where blue color molecules and yellow color molecules are symmetrical about 21 screw axes (represented by the gray arrow) along the c-axis at 223 K. c Packing view of S-SEA-Si. The dashed lines denote the distance between the adjacent N atoms. H atoms are partly omitted for clarity.