Compression-induced effect on the electronic structure of cyclotrimethylene trinitramine containing an edge dislocation

An effect of a hydrostatic compression on the electronic structure of cyclotrimethylene trinitramine (C3H6N6O6), also known as RDX, with an edge dislocation has been studied by means of the ab initio Hartree-Fock method for a periodic system combined with the many-body perturbation theory. An external pressure causes a significant decrease of the optical gap for both the perfect material and the crystal with dislocations. The edge dislocations produce local electronic states in the optical gap whereas the external pressure moves these states deep within the band gap. This contributes strongly to properties of the RDX crystals creating favorable conditions for the N-NO2 chemical bond rupture due to exciton formation. The relationship between the edge dislocations, hot spot formation, and the sensitivity of RDX to detonation are discussed in detail. (C) 2000 American Institute of Physics. [S0021-8979(00)03005-X].