The structure of the title compound, C 8 H 16 N 4 , which consists of four fused seven-membered rings, has been redetermined at 173 K. This redetermination corrects the orientation of two H atoms, which were located at unrealistic positions in the original room-temperature study [Murray-Rust (1974). J. Chem. Soc. Perkin Trans. 2 , pp. 1136–1141]. The complete molecule is generated by -42 m symmetry, with one quarter of a molecule [one N atom (site symmetry m ), two C atoms (one with site symmetry m and the other with site symmetry 2) and two H atoms] in the asymmetric unit. No directional interactions beyond van der Waals contacts are apparent in the crystal structure.