Fig. 1. Structure of the nanostar dendrimer [7].

Fig. 2. (a) and (b) Trimers used for geometry optimization; (a₁) and (b₁) monomer segments used for determining Ω₁, μ₁, and Ω₂, μ₂; (a₂) and (b₂) dimer segments used for determining J_00′ and J_11′; (a₃) and (b₃) dimer segments used for determining J₀₁ and J₁₂.

Fig. 3. (c) and (d) Trimers used for geometry optimization; (c₁) and (d₁) monomer segments used for determining Ω₃, μ₃, and Ω₄, μ₄; (c₂) and (d₂) dimer segments used for determining J_22′ and J_33′; (c₃) and (d₃) dimer segments used for determining J₂₃ and J₃₄.

Fig. 4. Solid line calculated absorption spectrum of the nanostar with the parameters of Table 1 and Γ=806 cm⁻¹; dashed line experimental spectrum [7]. The arrows indicate the zero-phonon absorption peaks. The calculated spectrum was shifted to the blue by 33 nm to make the highest peak coincide with experiment.

Excitation energies Ω, exciton transfer J parameters and transition dipole moments μ of the Frenkel Hamiltonian. Ω and J are in cm⁻¹, μ are normalized relative to μ₁