Abstract:The crystal data of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50), dihydroxylammonium azotetrazole-1,1′-diolate (ATZO-1), and sodium 5,5′-azotetrazole-5-oxide pentahydrate (ATO-Na) were analyzed and compared. The effects of the introduction of ─NN─ and ─NN(O)─ into the structure of bis-tetrazolium molecules was summarized from the micro-level. Results show that the bistetrazole linked from two tetrazolium rings directly has the densest structure among three compounds, the symmetrical and compact structure further make it own the highest crystal density. Based on the Born-Haber cycle and the Hess law, the heat of formation for TKX-50, ATZO-1 and dihydroxylammonium 5,5′-azotetrazole-5-axide (ATO-1) were calculated. According to the Kamlet Jacobs formula (K-J equation), detonation parameters of these three compounds were also obtained. By comparison, it could be found that both the introduction of ─NN─ and ─NN(O)─ bonds can increase the enthalpy of formation for compounds to a certain extent. However, due to the apparent density difference in three crystals, TKX-50 still holds the highest detonation value.