[en] Highlights: • Extremely flat twisting potential is predicted for DABCO. • M11 and MN12-SX functionals are recommended. • Entropic effects play important role in stabilization of twisted conformers. The energy and structural parameters of 1,4-diazabicyclo[2.2.2]octane (DABCO) obtained by various DFT methods are examined versus ab initio and experimental data. The features of twisting potentials of DABCO and closely-related species (1-azabicyclo[2.2.2]octane and bicyclo[2.2.2]octane) are discussed in light of computational schemes applied.