The (R)-OH-Q-compounds consist of a (R)-(-)-3-hydroxlyquinuclidinium-molecule ((R)-OH-Q) and a halogen (Cl/Br/I) ion. The comparison of these compounds, allows for the investigation of the role of electronegativity of the anion and halogen size in the plastic organic crystals. Figure , left panel, shows the crystal structures of the compounds in this group. They all pack in the same P4 1 space group. While all three are reported as ferroelectrics , the experimental polarization has only been reported for (R)-OH-QCl. The right panel of Fig. shows a strained structure. Unlike in the quinuclidinium-compounds, there is no clear molecular rotation in the strained unit cell, indicating that the piezoelectricity arises from an extender mechanism similar to the inorganic extender piezoelectrics, like PbTiO 3 and AlN. The anisotropies in the (R)-OH-Q compounds are quite comparable to that of LiTa which has a piezoelectric anisotropy of 3.3 .