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In order to discover more potential high energy compounds, five computer-aided design methods were founded, and 20 high energetic compounds based on the 1,2,3,4-tetrazine-1,3-dioxide frame were designed. The first step of computer-aided design methods was to design new frame M. Three combination rules were invented, they were simple double-points rule, complicated double-points rule, and complicated multi-points rule. The second step of computer-aided design methods was to design 1,2,3,4-tetrazine 1,3-dioxides derivants by connecting M to 1,2,3,4-tetrazine-1,3-dioxides. Two combination rules were invented, they were simple single-points rule and double-points rule. All the structures are ring-fused or caged compounds including 1,2,3,4-tetrazine-1,3-dioxide. In these compounds, almost half of them have positive or zero oxygen balances, and the nitrogen contents of 17 compounds are over 40%. The densities and detonation velocities of all compounds are over 1.98 g cm−3 and 9500 m s−1 respectively. -N = N- group and -NO2 group have a major contribution to enthalpy of formation, detonation heat, and power index. -O- group and -ONO2 group have the main contribution to density, detonation velocity, and detonation pressure.

In order to study the effects of N-oxide on structure and performance, six categories of energetic compounds were systemically investigated. The results indicated that the C-C bonds in the rings were shortened, and the C-N bonds close to the N → O bond were elongated when N atoms was oxidized to form N → O bonds. N → O bonds can increase the densities of most categories of compounds, and the increment will increase with the number of N → O bonds. As to their detonation performances, almost all categories of compounds had an increased trend, except for some NO2-, NHNO2- and ONO2-substituted compounds. The contribution of 1,2,3,4-tetrazine and 1,2,4,5-tetrazine to performances was better than that of pyrazine and [1,2,5] oxadiazolo [3,4-b] pyrazine on the whole, and the groups, especially energetic groups, made a huge contribution to performance. When R was a NH2 or ONO2 group, all compounds had lower impact sensitivities, and thus represent candidates for novel energetic compounds. However, other than the sixth category of compounds, all compounds had higher impact sensitivities when R was a NO2 or NHNO2 group, and have little significance in application.

The structural characteristics involving thermal stabilities of liquid nitromethane (NM)—one of the simplest energetic materials—confined within a graphene (GRA) bilayer were investigated by means of all-atom molecular dynamics simulations and density functional theory calculations. The results show that ordered and layered structures are formed at the confinement of the GRA bilayer induced by the van der Waals attractions of NM with GRA and the dipole–dipole interactions of NM, which is strongly dependent on the confinement size, i.e., the GRA bilayer distance. These unique intermolecular arrangements and preferred orientations of confined NM lead to higher stabilities than bulk NM revealed by bond dissociation energy calculations.

In order to seek the potential high energy density compounds (HEDCs) with excellent performance and satisfactory safety, some combination rules are presented and 15 HEDCs are designed and sifted, and followed by the properties predicting. From the results, HEDC-3, HEDC-4, HEDC-9, HEDC-10, HEDC-11, HEDC-12, HEDC-13, and HEDC-14 have good comprehensive properties. They are furoxan, fused ring or cage-type compounds, whose frame is composed of some single ring by single (double or multi) point addition. Their densities are over 1.95 g cm(-3), and detonation velocities are over 9500 m s(-1). Their BDEs are over 85 kJ mol(-1), and the values of available free space (∆V) are lower than the ∆V of β-CL20 (∆V = 86). In view of the synthesis feasibility, the synthesis routes of HEDC-4, HEDC-9, HEDC-10, HEDC-12, HEDC-13, and HEDC-14 have been designed.

The stability of energetic materials confined in the carbon nanotubes can be improved at ambient pressure and room temperature, leading to potential energy storage and controlled energy release. However, the microscopic structure of confined energetic materials and the role played by the confinement size are still fragmentary. In this study, molecular dynamics simulations have been performed to explore the structural characteristics of liquid nitromethane (NM), one of the simplest energetic materials, confined in a series of armchair single-walled carbon nanotubes (SWNTs) changing from (5,5) to (16,16) at ambient conditions. The simulation results show that the size-dependent ordered structures of NM with preferred orientations are formed inside the tubular cavities driven by the van der Waals attractions between NM and SWNT together with the dipole-dipole interactions of NM, giving rise to a higher local mass density than that of bulk NM. The NM dipoles prefer to align parallel along the SWNT axis in an end-to-end fashion inside all the nanotubes except the (7,7) SWNT where a unique staggered orientation of NM dipoles perpendicular to the SWNT axis is observed. As the SWNT radius increases, the structural arrangements and dipole orientations of NM become disordered as a result of the weakening of van der Waals interactions between NM and SWNT.