Also known as C2h-N6
Hexanitrogen (diazide, hexaaza-1,2,4,5-tetraene) is an allotrope of nitrogen with the formula N6. The six nitrogen atoms are all covalently bonded in a single molecule: two azide units linked to each other. Its stability and structure were theorized in 2016 and its synthesis was reported in 2025. It is stable at cryogenic temperatures. The higher symmetry analogue, the benzene-like cyclic hexazine, has remained only theoretically hypothesized.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).