The values of bond dissociation energies, BDE, of the weakest N–N bonds and total energies, Etotal, of molecules have been calculated for 14 cyclic nitramines by means of the UB3LYP/6-31G* and UB3LYP/6-31 + G* // PM3 methods. The relationships found between the BDE values and logarithms of impact sensitivity of these nitramines, expressed as drop energy, Edr, are not unambiguous. Replacement of these BDE values by the BDE/Etotal ratio has not resulted in any simplification of the said relationships, but their quality improved, particularly with application of the UB3LYP/6-31 + G* // PM3 (UHF) method. The reason of ambiguity of the relationships found mainly lies in real conformation of the respective molecules and intermolecular force effects in real molecular crystals, which are included in neither of the two calculation methods.