TEX is an explosive with interesting isowurtzitane cage structure. It exhibits successful explosion performance and good sensitivity. Herein, the tendency of TEX to form hydroperoxide structure under storage conditions was examined by density functional treatment. Additionally the possible decomposition products of the hydroperoxides were investigated. Moreover, the detonation performance values for TEX itself and two isomeric hydroperoxide derivatives were calculated. Detonation products and explosive power index values were investigated and the effect of O-2 molecule on sensitivity and detonation properties was studied.