Example 3 a Hybrid Salt-Co-crystal

Building unit formed by one molecule of (grey), two molecules of A (black) and two molecules of AH (orange) adapted from Ref 6. 

3 Co-crystals of Alike Molecules (including Enantiomers, Isomers, Diastereomers. ..) 

When two components are mirror related molecules (i.e. optical antipodes or enantiomers), special relationships link them. For instance, they have equal non-vectorial intensive properties (temperature and enthalpy of fusion, etc.) and are opposite in sign but have equal absolute values of vectorial properties 

Although there is a priori no restriction in symmetry applicable to the space group of the racemic compound crystal lattice, a clear majority of these racemic compounds crystallize in one of the 92 centrosymmetric space groups among them Fife, P-l, C2/c, Pbca, Pnma are by far the most popular. . 

Some chiral racemic compounds crystallize in the 73 non-chiral and non-centrosymmetric space groups such as Pc, Pnali (form III of rae modafi-niii8,i9) Fddl (form IV rac-modafiniP°), and so on. Very rare examples 

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