For tetramer 3.5 Å and SAM 3.5 Å, the ππ * lifetimes are longer, ∼3.4 and 3.8 ps, respectively. Inspecting populations of individual states, we observe that the S 5 state (the lowest ππ * state) is rapidly populated in all cases (Figure ). However, it is populated slower and also decays slower for models with a = 3.5 Å than for models with a = 5.5 Å (Figure ). In this respect, we note that for the dimeric models with a = 3.5 Å studied in Ref. 33 the ππ * lifetime for the SAM was reduced by a factor of 3 with respect to the free dimer. A possible reason for this discrepancy is another electronic structure method used in Ref. 33 (including more orbitals and excitations).