Three pairs of very closely related structures for three molecular solids have been determined at or above the temperature of crystal growth. In two cases the two phases are so similar that it seems surprising that they can co-exist. In the third case one of the structures seems to be a combination of a highly disordered structure that might be found in the smallest crystal nuclei and of the fully ordered structure that is seen at 130 K In all three systems it seems possible that a transition to the phase with the larger unit cell takes place sometime after crystal nucleation.