A theoretical NMR study of polymorphism in crystal structures of azoles and benzazoles.

The NMR chemical shifts of two azoles and one benzazole whose crystal structures present polymorphism have been computed using the GIPAW approach. N and C nuclei have been studied. Statistical analysis of the computed C and N chemical shifts indicates that the GIPAW chemical shifts reproduce with a high degree of accuracy those experimentally reported. This methodology can be used to identify other polymorphic crystal structures.