To enable a comparison to the monomer dynamics at (approximately) the same level of theory, we performed SH simulations for a single AB molecule using rAM1/FOMO-CIS with a small active space including only HOMO-1, HOMO, and LUMO (see Figure ), thus resulting in five Slater determinants to represent the wave functions of the mononer. Three singlet states (S 0 , S 1 , and S 2 ) were used in the SH simulations for the monomer. The two atoms in a para position (C and H) were fixed, similarly to the tetramer cases.