Simple rule for linking atoms to construct high energy isomers

The present work concerns a basic issue in molecular science, i.e., constructing a high energy isomer with a given composition. Three compositions of CH₃NO₂, CH₄N₂O₂, and CH₃NO₃ are adopted to construct various isomers with the internal energy calculated and compared to ascertain its dependence on the linking order of atoms. Thereby, a simple rule for constructing high energy CHNO isomers is summarized. The separation of reducing C/H atoms and oxidizing O atoms by N atoms as well as the direct linkage of C-C, C-H, and O-O, benefits for high energy; on the other hand, the O-O linkage leads to low molecular stability, and thus the separation of double O atoms by a N atom is necessary to build a stable energetic molecule. The direct linkage of C-O and O-H significantly weakens or diminishes the activity of related atoms, and the O atoms can thus be called died O atoms. This rule is expected to promote the screening of high energy molecules in the fields of fuels and energetic materials.