As the direct full-system CIS calculation cannot predict such TT-DLE states (or other double-local excited states), we performed a direct CISD/SVP calculation using all single and double excitations from a set of 9 occupied orbitals to 8 virtual orbitals (via a RAS1+RAS3 scheme described in Section 4) to assess the validity of the encountered TT-DLE states. We note that the employed active orbitals (see Section 4) should be sufficient to obtain all four full-system 1 ππ * 3 , 1 ππ * 4 , and 1 nπ * 3 LE and all TT-DLE excitonic configurations. Table shows the dominant characters of the CISD calculation in the last column. As can be seen, the first eight singlet states obtained by direct CISD correspond to the states of ECIS, and no dominantly DLE state was found at low energies. However, the S 9 and S 10 states are found to dominantly be CT states between pairs of guanines. Then, the S 11 state was found to match the S 4 state of ECISD, dominantly corresponding to the TT-DLE configuration. It is important to note that the state ordering of the performed direct CISD calculation has to be taken with caution, due to the very small number of active orbitals and the generally inadequate description of the dominantly doubly-excited states (due to the lack of triple excitations in CISD). Hence, to more rigorously verify the accuracy of TT-DLE states obtained by ECISD, one should perform more rigorous direct full-system calculations, including more active MOs and larger CI (or CI-like) expansions, which exceeds the scope of the present work. Nevertheless, from the presented comparison, it is clear that, although not matching the state ordering of direct CISD calculation, the ECISD is apparently capable of producing states dominated by both LE and TT-DLE excitonic configuraitons.