in meteorites, and the chemical evolution of organic inventory under extraterrestrial conditions is of increasing interest. To understand the intermolecular interactions of D and U in the solid state, we solved the crystal structures of D-U hyd from SCXRD data (Figure ) and D-U anhyd from 3D ED data (Figure and S17). D-U hyd is a 1:1 stoichiometry cocrystal channel hydrate whose asymmetric unit comprises D and U molecules assembled by three intermolecular hydrogen bonds and disordered water molecule (Figure ). In the crystal, D and U molecules form hydrogen-bonded layers with D-U and D-D hydrogen bonding (Figure ). Interestingly, each D molecule forms eight hydrogen bonds, thus involving all possible hydrogen bonding donors and acceptors. Besides filling structural voids and lying in the channels (Figure ), the disordered water molecules act as bridging elements connecting adjacent layers through hydrogen bonding (Figure ). On the other hand, D-U anhyd is a 1:2 stoichiometry cocrystal anhydrate whose asymmetric unit contains two molecules of U and one molecule of D (Figure ). Besides D-U interactions, hydrogen-bonded layers also exhibit homomeric U-U hydrogen bonding interactions (Figure ). Similarly, each D molecule forms eight hydrogen bonds, involving all possible hydrogen bonding donors and acceptors. Between the layers, this crystal also exhibits homomeric parallel displaced π-π stacking interactions distanced at 3.7 Å (Figure ). inter-layer hydrogen bonds. Besides, in D-U anhyd we observe small distortions from coplanarity. More details on calculation parameters and related analysis can be found in the Experimental Section as well as Table and.