HMX (an acronym for High Melting eXplosive) is a powerful military explosive material; it is also used in rocket fuels. It may be produced by nitration of hexamine in the presence of acetic anhydride, paraformaldehyde and ammonium nitrate.
HMX, also known as octogen, explodes violently at high temperatures. It decomposes around 280°C. Its density is 1.91.
HMX is the military's most powerful conventional (non-nuclear) explosive, though Octanitrocubane is expected to be more powerful.
The molecule has an eight-membered ring made of carbon and nitrogen atoms, which supports four nitro groups.