Octanitrocubane (molecular formula: C8(NO2)8) is a proposed high explosive that, like TNT, is shock-insensitive (not readily detonated by shock).

For this reason, heptanitrocubane, the slightly less nitrated form, is believed to have marginally better performance, despite having a worse oxygen balance.

This increase in power is due to its highly expansive breakdown into CO2 and N2, as well as to the presence of strained chemical bonds in the molecule which have stored potential energy.

In addition, it produces no water vapor upon combustion, making it less visible, and both the chemical itself and its decomposition products (nitrogen and carbon dioxide) are considered to be non-toxic.

Philip Eaton's synthesis was difficult and lengthy, and required cubane (rare to begin with) as a starting point.