For the tetrameric models, the nπ * lifetimes are prolonged, moderately for models with a = 5.5 Å (∼2.4 ps for tetramer 5.5 Å and ∼1.9 ps for SAM 5.5 Å), stronger for tetramer 3.5 Å (∼5.9 ps), and the most for SAM 3.5 Å (∼18.7 ps). The long nπ * lifetime for tightly packed SAM 3.5 Å is in qualitative agreement with previous simulations of azobenzene-containing SAMs. At that, the internal conversion to the S 1 state is extremely fast for all studied models -S 1 is populated almost completely within ≲10 fs (see Fig. ). This result may be expected since the nπ * exciton splittings are small, and it is again in agreement with ref. exciton transfer pathway as discussed above (see Fig. ).