To look for high energy density materials (HEDM), the relationships between the structures and the performances of polynitroadamantanes (PNAs) were studied. The assigned infrared spectra of PNAs obtained at the density functional theory (DFT) B3LYP/6-31G level were used to compute the thermodynamic properties on the basis of the principle of statistical thermodynamics. The thermodynamic properties are linearly related with the number of nitro groups as well as with the temperatures. Detonation properties of PNAs were evaluated by using the Kamlet-Jacobs equation based on the calculated densities and heats of formation for titled compounds, and it is found that only when the number of nitro groups of PNA is equal to or more than eight can it be possible for PNAs to be used as HEDMs. The relative stabilities of PNAs were studied by the pyrolysis mechanism using the UHF-PM3 method. The homolysis of the C-NO2 bond is predicted to be the initial step of thermal decomposition. The activation energies (Ea) for the homolysis decrease with the number of nitro groups being increased on the whole. The stability order of dinitroadamantane isomers derived from the interactions among nitro groups is consistent with what is determined by Ea. The relations between the Ea's and the electronic structure parameters were discussed. In combination with the stability, PNA (1,2,3,4,5,6,7,8,9,10-) is recommended as the target of HEDM with insensitivity.

DFT and TDDFT calculations have been carried out to investigate the effect of donor and acceptor groups on the electronic properties of zinc-porphyrin sensitizers. The calculated results show that increasing the electron releasing strength of a meso-donor group opposite to a meso substituted acceptor group increases the light harvesting efficiency and short circuit current density.

Density Functional Theory (DFT) was employed to study the geometries, electronic structures, infrared vibrational spectra, and thermodynamic properties of seven isomeric cyclic nitramines of C 6 H 10 N 8 O 8 (i.e., TNAD and its six isomers) at the B3LYP/6-31G* level of theory. The experimental results available for TNAD were used to determine the reliability of the DFT method for generating structural and IR spectroscopic values for these molecular systems. The relative stabilities of the conformers were evaluated from the energy differences of the structures. Detonation properties of various conformers were evaluated using the Kamlet-Jacobs equations, and it was found that all the calculated results are comparable to the available experimental data. In addition, the calculated results demonstrate that all title compounds can be used as excellent propellant ingredients.

Density functional theory (DFT) was employed to evaluate the heats of formation (HOFs) for hexaazaadamantane (HAA) derivatives with OCN, ONC, and OONO 2 groups, respectively. This was done by designing isodesmic reactions at the B3LYP/6-31G* level of theory, where the HAA cage skeletons were kept unbroken to produce more accurate results, and all HOFs for the required reference compounds, NH 2 CN, NH 2 NC, NH 2 ONO 2 , and (CH 2 NH) 3 , were derived from the G 3 theory calculation based on the atomization energies. The calculation results show that the HOFs of HAA derivatives are mainly affected by the number and the position of substituent groups, all the obtained HOFs are positive, and the ONC derivatives have the most HOFs among the three types of derivatives with the same number of substituent groups. The detonation velocity (D) and detonation pressure (P) were obtained from the empirical Kamlet-Jacobs equations. All the ONC and OCN derivatives of HAA have lower densities (), heats of explosion (Q), D, and P. However, these properties of OONO 2 derivatives are rather high and vary with the number of OONO 2 groups. Considering the easiness for synthesis and relative stability, 2,4,6,8-hexaazaadamantanenitrate is finally recommended as a potential candidate of a high-energy density compound (HEDC).

Di-tetrazine-tetroxide (DTTO) was predicted in 2001 to have a density (up to 2.3 g cm À3) and heat of detonation (up to 421.0 kcal mol À1) better than other explosives, making it the "holy grail" of energetic materials (EMs), but all attempts at synthesis have failed. We report Density Functional Theory (DFT) molecular dynamics simulations (DFT-MD) on DTTO crystal for the two most stable monomers. We predict that the most stable isomer (c1) has a density of r ¼ ), a unique initial reaction among EMs. These results suggest that DTTO may have a higher thermal stability (barrier >7.0 kcal mol À1 higher) than RDX, HMX, and CL-20.