An effect of hydrostratic compression on deffects in energetic materials: ab initio modeling

摘要

First-principle theoretical investigation of the baic defects sucyh as a molecular vacance, a vacancy dimer, an edge dislocation, and a micro-crack in organic explosive molecular crystals is presented. As an example we considered solid RDX (C_3H_6N_6O_6) which is well studied unstable solid. It was established that external hydrostatic proessure changes optical properties of defect-free RDX as well as of the crystal with defect narrowing the band gap. The lattice defects (expecially dislocations) are identified with the so-celled "hot spots". The nature of local electronic states introduced in the band gap by the edge dislocation and formed maninly by molecular orbitals of N-NO_2 group is analyzed. Favorable conditions for molecular dissociation due to electronic excitation are shown.