On the basis of the framework of cubic gauche nitrogen (cg-N), six one-eighth methanetriyl groups (>CH-) substitutes and fifteen one-fourth >CH- substitutes were optimized using the first-principle calculations based on density functional theory (DFT). Both one-eighth and one-fourth substitutes still keep the gauche structures with the simple formula CHN7 and CHN3, respectively. The most thermodynamic stable gauche CHN7 and CHN3 are P21 qtg-C2H2N14 I and P21 qtg-C4H4N12 III, respectively. No probability density of C-C single bonds and high probability densities of C-N-C structures were found in the two substitutes. Although gauche CHN7 and CHN3 lose energy density in contrast to cg-N, they win kinetic stability and combustion temperature (Tc). Thus, they are more feasible than cg-N, and more effective than the traditional rocket fuels.
Keywords: Density functional theory; High energy density materials; Nitrogen-rich substances; Specific impulse.
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