Identification of chemical entities. A reaction could be very vigorous and, in this case paramagnetic, and the reaction products were identified by crystallography on sequential crystallization.

Precise measurement of a structural feature. The efficiency of a catalyst could depend on whether the active site can accommodate substrate molecules!

Understanding molecular geometry. Does your model pharmaceutical have the necessary shape for bioactivity?

Understanding the “spaces” between molecules. Does your novel material have the correct porosity?