For this system, ππ * correlation within each individual benzene (intra-fragment) is expected to be dominating, while electron correlation across the fragments is expected to be weaker, and its role becoming increasingly important as the benzene fragments get closer to each other. A GAS [5 • (6, 6)] active space has been chosen, which consists of the 30 π-orbitals, six on each benzene, and their 30 electrons. The six π-orbitals of each benzene have been grouped into separate GAS subspaces. We used cumulative