The case of disconnected spaces, n exc = 0, is equivalent to a system of neutral fragments, whose π-electrons are internally correlated and that interact among each other only via the mean field generated by the local (6, 6) active space expansion. For n exc ≥ 1, chargetransfer configurations are added to the wave function and many-body correlation effects are explicitly correlated. Hence, convergence with respect to n exc was reached earlier for larger distances between neighboring benzene molecules.