Abstract: | Density Functional Theory (DFT) calculations have been performed on the high explosive compound tetranitrotetraazabicyclooctane (bicyclo‐HMX) in gas phase employing the self‐consistent field (SCF) theory and in different solvents, i.e. cyclohexane, dichloroethane, ethylalcohol, acetonitrile, and water, utilizing the self‐consistent reaction field (SCRF) theory at a B3LYP/6–31 1G** level of theory. Reasonable agreement has been found between the computed and the available experimental data. The effects of different solvents on the geometry, electronic structure, and vibrational frequencies are discussed. Various solvents under consideration are found to have similar effects on the above properties. But some properties change regularly with the increasing polarity of the solvents, and the stronger the solvent polarity is, the larger the change is. In addition, based on the vibrational analysis, standard thermodynamic properties of bicyclo‐HMX in gas phase are also computed by using the statistical thermodynamic principle. |