As a second example, we studied the 1:1 nicotinamide:benzoic acid (GAZCES) co-crystal as a system with more degrees of freedom (due to two molecules in the asymmetric unit), but where the known polymorphs again have the same space group symmetry. Nicotinamide:benzoic acid is a highly polymorphic co-crystal; four polymorphs have been observed under mechanochemical co-crystallization conditions, but only polymorphs I and II have had their structures determined. Both characterized polymorphs are in space group P 2 1 /c.