The banding and electronic structures and some properties of crystalline β-HMX are investigated at DFT-B3LYP/6-31G level. The crystalline β-HMX may be an insulator, which is judged from its band gaps about 5.7 eV. The heat of sublimation is predicted to be 154.08 kJ.mol^-^1 that is in good agreemnet with the experimental data. The point charge electrostatic potential is very high between the nitro groups of the neighboring molecules, which indicates that the crystal lattice in this positio may easily be broken adn becomes the explosion center when β-HMX is impacted. From the distance of atoms and the overlap population analysis, it is found that weak H-bonds exist between molecules of β-HMX and the bonds of N-NO2, N-C in β- HMX are weaker than others, which predicts that these two positions are susceptible to breaking down and causing explosion.

Key words: HMX, BAND STRUCTURES, ELECTRONIC STRUCTURE, CRYSTAL STRUCTURE, EXPLOSIVES