Coulomb shape dependence

The TDC method takes into account the shape of the molecules in detail, and its accuracy in the calculation of the Coulomb coupling depends only on the size of the volume elements used in the grid (the cube ). In this way, the TDC method has proven extremely useful in understanding the limitations of the point dipole approximation (PDA) in a variety of systems. In particular, how the PDA fails to describe the coupling when the interchromophoric center-to-center distance is comparable to the molecular dimensions, a situation found, for example, in many of the relevant interactions present in natural light-harvesting antennas. [50]... 

Sn < 0, eV < Sn+1. In quantum dots, Sn depends linearly on the bias V and gate Vg voltages. Thus, in the Vq — V plane regions with zero current are confined within Coulomb diamonds, that are identical diamond-shape structures repeating along the Viy-axis. 

The primary acceptors of the two plant photosystems differ fundamentally from each other, no doubt because of their different redox midpoint potentials (about -100 to -200 mV for PS II, -705 to -730 mV for PS I [R3-R5]). In PS I two iron-sulfur (ferredoxin-type) proteins, and Fg, with characteristic EPR spectrum in the reduced state ( m between -450 and -550 mV), have been observed (Fig. 2) that function either parallel or in series (see Ref. R5 for a recent review). The shape of the spectra of the two ferredoxin-type acceptors and in particular their principal g values depend on whether one or both acceptors are reduced (Fig. 2). It is unlikely that this is due to a magnetic interaction, as the differences depend linearly on the microwave frequency, i.e. on the applied magnetic field (exchange and dipolar interactions are independent of field Table 3) [16,42], Possibly, Coulomb repulsion causes strain-induced g shifts. 

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