In our previous work on the dimeric models, we found the following quantum yields: monomer, 21 %; dimer 3.5 Å, 19 %; dimeric SAM 3.5 Å, 11 %; and dimeric SAM 5.5 Å, 22 %. While the main observation of the reduced quantum yield in the densely packed SAM is qualitatively the same, we observe the following quantitative differences. First, in the previous work the quantum yield of the dimer 3.5 Å and SAM 5.5 Å are approximately the same as that for the monomer, but in the present work, for models with a = 5.5 Å and for tetramer 3.5 Å, the quantum yields are reduced by a factor of ∼3 with respect to the monomer. Second, whereas the quantum yield of the dimeric SAM 3.5 Å is reduced by a factor of ∼2 (but still is nonzero), no switching was observed for the tetrameric SAM 3.5 Å studied here. There are several possible reasons for these discrepancies: (i) the QM part is larger in the present work, four instead of two molecules, (ii) electronic structure methods are different in terms of orbital active space size and allowed excitations, (iii) in this work, the additional vdW term is used in the QM part to better describe noncovalent interactions, and (iv) the added potential is applied in the present work in contrast to the previous work.