Researchers and collaborators of the Extreme Conditions Chemistry Laboratory (ECCL) at the "Jožef Stefan" Institute (Klemen Motaln, Anton Kokalj, Kristian Radan, Mirela Dragomir, Boris Žemva and Matic Lozinšek), in collaboration with partners from the Institute of Physics of the Czech Academy of Sciences (Kshitij Gurung, Petr Brázda and Lukáš Palatinus), have for the first time successfully employed 3D electron diffraction on nanocrystals to determine the crystal structures of reactive xenon compounds. To accomplish this, the team developed a specialized procedure for handling and transferring extremely reactive and air-sensitive substances, ensuring their safe introduction into a transmission electron microscope. This method paves the way for structural analysis of other reactive and sensitive compounds and materials, particularly those for which single-crystal growth is challenging, rendering traditional X-ray diffraction methods ineffective. This study, funded by GA ČR and ARIS as part of the CEUS joint research project, was published in ACS Central Science, where it was highlighted on the cover. The American Chemical Society (ACS) also featured the research in a press release.