Molecular dynamics study on the correlation between structure and sensitivity for defective RDX crystals and their PBXs.

Molecular dynamics simulation was applied to investigate the sensitivities of perfect and defective RDX (cyclotrimethylene trinitramine) crystals, as well as their PBXs (polymer-bonded explosives) with the polymeric binder F(2311), in the NPT (constant number of particles, constant pressure, constant temperature) ensemble using the COMPASS force field. Five kinds of defects-two dislocations, one vacancy, and two types of doping-were considered separately. The bond length distribution and the maximum (L (max)) and average (L (ave)) bond lengths of the N-NO(2) trigger bonds in RDX were obtained and their relationships to the sensitivities of RDX and PBXs are discussed.

Theoretical studies of solid bicyclo-HMX: effects of hydrostatic pressure and temperature.

On the basis of density functional theory (DFT) and molecular dynamics (MD), the structural, electronic, and mechanical properties of the energetic material bicyclo-HMX have been studied. The crystal structure optimized by the LDA/CA-PZ method compares well with the experimental data. Band structure and density of states calculations indicate that bicyclo-HMX is an insulator with the band gap of ca.

Molecular dynamics simulations of trans-1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin-based polymer-bonded explosives.

Molecular dynamics has been applied to investigate the low-sensitivity explosive TNAD (trans-1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin)-based polymer-bonded explosives (PBXs) with four typical fluorine polymers, PVDF (polyvinylidenedifluoride), PCTFE (polychlorotrifluoroethylene), F(2311) (fluorine rubber), and F(2314) (fluorine resin). The elastic constants, mechanical properties (tensile modulus, bulk modulus, shear modulus, and Poission ratio), binding energies, and detonation performances are first reported for the TNAD-based PBXs. The results show that the mechanical properties of TNAD can be effectively improved by the addition of small amounts of fluorine polymers, and the overall effect of fluorine polymers on the mechanical properties of the PBXs along three crystalline surfaces is (001) > (010) > (100).

Ab initio and molecular dynamics studies of crystalline TNAD (trans-1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin).

The structural and electronic properties of the energetic crystal TNAD (trans-1,4,5,8-tetranitro-1,4,5,8- tetraazadecalin) have been studied using plane-wave ab initio calculations based on the density function theory method with the ultrasoft pseudopotentials. It is found that the predicted crystal structure is in good agreement with experimental data and there are strong inter- and intramolecular interactions in bulk TNAD. Band structure calculations indicate that TNAD is an insulator with the band gap of ca.

Molecular dynamics simulations for pure epsilon-CL-20 and epsilon-CL-20-based PBXs.

Molecular dynamics has been employed to simulate the well-known high energy density compound epsilon-CL-20 (hexanitrohexaazaisowurtzitane) crystal and 12 epsilon-CL-20-based PBXs (polymer bonded explosives) with four kinds of typical fluorine polymers, i.e., polyvinylidenedifluoride, polychlorotrifluoroethylene, fluorine rubber (F(2311)), and fluorine resin (F(2314)) individually.