Effect of an intermediate composition on the maximum polarization. Left panel: BPCA clusters with R_V = 1.6 μm and R₀ = 400 nm with five-composite materials (silicate, water ice, amorphous carbon, organics, and troilite); f_org represents a mass fraction of organics with respect to total carbonaceous materials (organics + amorphous); f_org = 0.0 and 1.0 mean the carbonaceous component is pure amorphous carbon and organics, respectively. Right panel: Same as Fig. 7, but for BPCA clusters with R_V = 1.6 μm and R₀ = 400 nm with five-composite materials.