Symmetric triaminotrinitrobenzene known as TATB decomposes in contact with some heavy metals, such as copper. Presently, TATB and some of its important tautomers are subjected to B3LYP/6-31G(d,p) level of treatment. Some molecular orbital energies have been obtained and compared. Then, interaction of these species with Cu and Cu+ are investigated. Although TATB has been found to be affected little by either Cu or Cu+, undergoing only some bond length changes and/or distortions, the resonance-assisted tautomers having one to three aci groups decompose by the influence of Cu atom. In each case, only one N-OH bond rupture occurs. (c) 2018 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).