A simple rotational isomeric state model was used to detect the degree to which polyimide repeat units might align to give an extended crystal. It was found experimentally that the hallmarks of stretch-crystallization were more likely to occur in materials whose molecules could readily give extended, aligned conformations. A proposed screening criterion was 84% accurate in selecting crystallizing molecules. Hinkley, Jeffrey A. and Dezern, James F. Langley Research Center NASA/TM-2002-211418, NAS 1.15:211418, L-18142