(a) Position of bacteriochlorophylls (P M , P L , B M , B L ) and bacteriopheophytins (H M , H L ) in the reaction center (RC) from Rhodobacter sphaeroides. (b) RC equilibrium infrared absorption spectrum from Ref. 5 . (c) Light harvesting complex 1 surrounding the RC; shown is also the B875 ring of pigments. (d) Orientation of bacteriochlorophyll and bacteriopheophytin transition dipole moments in the RC.
Comparison of 300 K linear equilibrium absorption spectra calculated by the HEOM and observed experimentally as reported in Ref. 5 .
Excitation dynamics of the reaction center calculated with system and bath parameters taken from Table I , where parameter set 1 (a) assumes high dynamic disorder and parameter set 2 (b) assumes low dynamic disorder. Populations are shown for the pigments initially excited in each calculation.
Reaction center exciton states. The exciton states, , are defined as eigenstates of the stationary state density matrix, namely, ; parameters were taken from Table I , where parameter set 1 (a) assumes high dynamic disorder and parameter set 2 (b) assumes low dynamic disorder. Orange circles (radius scales with diagonal elements of ) indicate the participation of each pigment in an exciton state, and blue lines (thickness scales with absolute value of off-diagonal elements of ) indicate inter-pigment coherence. Listed are also the steady-state population P ν and energy εν of each exciton state. The numbering of the states is in energetically ascending order.
(a) LH1 absorption spectrum. Shown is a comparison of spectra from Ref. 66 and calculated here using the HEOM approach, but excluding static disorder. (b) Excitation transfer from LH1 to RC. Excitation transfer was determined both for parameter sets 1 and 2. Shown are close comparisons between the HEOM results and descriptions in terms of the kinetic model in Eq. (10) where t f is the LH1→RC transfer time and t b is the RC→LH1 transfer time.
Parameters for the RC Hamiltonian, H S , and spectral densities J n , obtained from fits to experimental spectra (all in cm−1).
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