Presentation of polymorphic structures for comparison

Therefore, plotting the structures so that the possibly common = cp axis is horizontal and the possibly doubled 2ca = bp axis is vertical greatly aids in making this eomparison. In faet, it is seen in Fig. 2.15 that in spite of the identity in space group and the apparent possible relationship between some eell eonstants of the two polymorphs, there is no similarity in the erystal struetures (see also Section 5.9, Fig. 5.17). 

An additional example will serve to demonstrate the similarities in structures that ean be revealed by taking care in the way they are plotted. The eell eonstants for the two forms of 5-methyl-1 -thia-5-azaeyelooetane 1 -oxide perehlorate (Paul and Go 

The two examples given in Figs 2.15 and 2.16 demonstrate another point that deserves emphasis, especially to non-crystallographers. The identity or non-identity 

Because hydrogen bonds are the strongest and most directional of intermolecular interactions, they have been the subject of study since the 1920s (Latimer and Rodebush 1920 Pimentel and McClellan 1960). The strength and directionality of these bonds might suggest a high incidence of polymorphism for those compounds which contain 

The two molecules in the asymmetric unit of Form I can be distinguished chemically. Neutral molecule A forms a C(6) using an amino-hydrogen and a carboxyl carbonyl (Fig. 2.19(c)) the zwitterion B has the same motif using an ammoniacal 

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