Figure 4.

Excitonic Connectivity between PSI Complexes within and across Trimers Corresponding to the Hexagonal Pattern in Figure 3.

Shown in (A) are the couplings H_MN,mn between pairs of pigments m,n of PSI monomers M,N, respectively, for M≠N; intramonomer couplings are not shown for clarity. The connections have cross sections proportional to the coupling |H_MN,mn|; couplings below 1/cm are not shown. Due to the approximate symmetry displayed by the PSI grid (Supplemental Figure 7), only the couplings of immediate neighbors of one PSI monomer (red in [A], I in [B]) are considered; two of the neighbors are in the same trimer (green in [A], II in [B]; blue in [A], III in [B]) and two are corresponding symmetry-copies in neighboring trimers (purple in [A], II' in [B]; orange in [A], III' in [B]). Excitation sharing between monomers is shown in (C) in terms of the trapping probability of excitation at RC_I as a function of initial site across the PSI monomers M = I, II, III, II', III' as indicated in (B). Chlorophyll number m corresponds to the order given in PDB:1JB0. As suggested by the connections in (A), excitation sharing within the monomers of the same trimer is more prominent than across trimers.