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 cyclo trimethylene trinitramine (C3H6N6O6), also known as RDX, with an edge dislo cation has been studied by means of the ab initio Hartree-Fock method for a periodic system combined with the many-body perturbation theory. An extern al pressure causes a significant decrease of the optical gap for both the p erfect material and the crystal with dislocations. The edge dislocations pr oduce local electronic states in the optical gap whereas the external press ure moves these states deep within the band gap. This contributes strongly to properties of the RDX crystals creating favorable conditions for the N-N O2 chemical bond rupture due to exciton formation. The relationship between the edge dislocations, hot spot formation, and the sensitivity of RDX to d etonation are discussed in detail. (C) 2000 American Institute of Physics. [S0021-8979(00)03005-X].