@article{oai:nagoya.repo.nii.ac.jp:00030075,
 author = {Kitoh-Nishioka, Hirotaka and Shigeta, Yasuteru and Itoh, Shigeru and Kimura, Akihiro},
 issue = {2},
 journal = {The Journal of Physical Chemistry B},
 month = {Jan},
 note = {The excitonic couplings among 54 bacteriochlorophylls-g (BChl)-g, 4 BChl-g′, and 2 Chl-aF pigments were calculated in the type-I homodimeric reaction center (RC) of Heliobacterium modesticaldum (hRC) and compared with those in the photosystem I (PSI) type-I heterodimeric RC. The advanced combination of transition charge of electrostatic potential (TrESP) with the Poisson equation (Poisson–TrESP), applied for the first time to the excitonic coupling calculation, gave a reliable model in contrast to a model calculated by simple standard dipole–dipole interaction approximation that was qualitatively valid for hRC but not for PSI. The simplest method for the calculation of the long-range contribution to the excitonic coupling on RCs is shown to be the TrESP method, which considers a distance- and orientation-independent local-field/screening correction factor. The excitonic couplings of the special pairs, P800 in hRC and P700 in PSI, are also calculated by the fragment excitation difference scheme at the configuration-interaction singles (CIS) level, which considers the charge-transfer characteristics of the relevant excitonic states. The calculation realized that the reported parameter values for P800 and P700 were better than the Poisson–TrESP calculation. Virtual exchanges between Chl-a and BChl-g on hRC and PSI indicated that the difference between hRC and PSI arises from the different electronic structures of Chl-a and BChl-g pigments themselves and the different arrangements on hRC and PSI. The contributions of excitonic couplings to the functional properties and evolutionary modifications of hRC and PSI are also discussed., ファイル公開：2021-01-16},
 pages = {389--403},
 title = {Excitonic Coupling on a Heliobacterial Symmetrical Type-I Reaction Center: Comparison with Photosystem I},
 volume = {124},
 year = {2020}
}