The molecular geometry of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) was optimized at B3LYP/6-31G^** level. The population, vibrational frequency, bonding behavior and natural bond orbital analyses were performed. According to the results, all atoms of LLM- 105 are coplanar and the molecule is constituted by a π conjugative system except H; intensive intramolecular hydrogen bonds are involved in LLM-105, which increase the stability of the whole molecule; the C-N bond in C-NO2 with the smallest bond intensity was considered as the induced bond of thermal decomposition in LLM-105.

Key words: ENERGETIC MATERIAL, EXPLOSION, QUANTUM CHEMISTRY, NITRO COMPOUNDS, OXIDE, DIAMINE, PYRAZINE P