Relations between angles and sides

To finish the discussion of the relation between P and 6, we should note first that the smectic C -smectic A phase transition in FLCPs can be close to first order, and in that case the 6 T) curves are similar to curve (a) in Fig. 15 [48,106]. Second, two different experimental techniques are used to measure the tilt angle (Fig. 17). In the x-ray experiment, the layer thickness, J, is first measured from the small-angle scattering peak and compared with the calculated length of the molecule (for low-molar-mass LC ferroelectrics) or of the mesogenic side chain (for side-chain... 

The relations between the cell sides (a, b, c) and cell angles (a, y) are shown and the corresponding lattices are labeled P = primitive, I = body-centerei C = side-centered, F = face-centered, R = rhombohedral. 

Figure 16-19. A Tt-stacked arrangement of Ooci-OPV5-CN" molecules in the crystal lattice (view at a slight angle with respect to the long molecular axis). B lop-view (lop) and side-view (bottom) of two nearest-neighbor Oocl-OPV5-CN" molecules in the crystal. related by a translation along the ci-axis. The distance of 3.5 A corresponds to the shortest distance between two atoms on different molecules (sec Fig. 16-18 for details).

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