Using a transmission electron microscope, the group imaged nanocrystallites of three organic semiconductor compounds, including dPyr PDI (A), with the circles indicating particles selected for further analysis. The scale bar is two microns. Then, they used MicroED to generate diffraction patterns of the crystallites while rotating the sample; one snapshot is shown in (B). With software, they obtained the crystal structure from these diffraction patterns (C and D). A single molecule is shown in green. At NSLS-II with the help of CFN scientists, they collected GIWAXS measurements on thin films (E). By comparing the MicroED and GIWAXS results, they determined that the crystal structure in the nanocrystallites and thin films is the same (F). This comparison subsequently helped them determine the orientation of molecules in the films. Published in Chem. Commun., 2020, 56, 4204–4207.