The crystal structure of α-L-sorbose

Abstract

The difference between the balance points achieved by KNbO3 and BaTiO3 is apparent from Table 4.Both substances have the same differences between long and short K-O(2) or Ba-O(2) bonds (KA and KC of Fig. 4).For BaTiO3, however, the difference between long and short Ba-O(1) bonds is 0.1.2A, and between long and short O(1)-O(2) edges is 0.04 A, while for KNbO3 the relative magnitudes are roughly interchanged, being 0.04A and 0.10A respectively.This supports the earlier suggestion that the K-O(1) links are already in compression and resistant to further compression.By contrast, either Ba is intrinsically smaller than K or it is more capable of polarizing the O atom to give unequal bonds; again, both causes may cooperate in the observed effect.We put forward this qualitative treatment in the hope that it may direct attention to aspects of the structures where more rigorous treatment might lead to very profitable results.We wish to express our indebtedness to Dr R.