In Fig. , we show two different models, one of an isolated defect corresponding to a different molecular orientation, and one of an intergrowth of a "plane" of differently ordered molecules. In both cases, the local orientations remain favourable, i.e. nearest neighbour interactions (in the xy-plane for the isolated defect, and in all directions for the intergrowth) remain the same as in the ground state structures, and should thus be expected to be of low formation energy.