As part of an increased interest in amino- and nitro-substituted high-energy-density materials (as exemplified by FOX-7, 1,1-diamino-2,2-dinitroethylene), here we present calculated properties of aminonitroacetylene, NH2-C C-NO2. Our results indicate that while the specific enthalpy of combustion is less than that of acetylene, its specific enthalpy of decomposition is greater than that of TNT, and its predicted density is large enough to predict substantial high-energy-density properties for this substance.