  Nitrides in many ways are fascinating since they often appear as
superconductors, high energy density and hard materials. Though there exist a
large variety of nitrides, noble gas nitrides are long missing in nature.
Pursuit of noble gas nitrides has therefore become the subject of topical
interests, but remains as a great challenge since molecular nitrogen (N2, a
major form of nitrogen) and noble gases are both inert systems and do not
interact at normal conditions. We show through a swarm structure searching
simulation that high pressure can lift the reactivity of both N2 and xenon
(Xe), making chemical reaction of them possible. The resultant nitride has a
peculiar stoichiometry of XeN6, possessing a high-energy-density of
approximately 2.4 kJg-1, rivaling that of the modern explosives. Chemically,
XeN6 is more intriguing with the appearance of chaired N6 hexagons and an
emergent 12-fold Xe by acceptance of unprecedentedly 12 Xe-N weak covalent
bonds. Our work opens up the possibility of achieving Xe nitrides whose
formation is long sought as impossible.
