The CT character is predominantly due to three excited states, S 1 , S 4 and S 7 . Importantly, the lowest-energy state has CT character (S 1 state). This means that for any type of excitation, either directly by visible light or by energy transfer from the antenna system, the Chl D1 Pheo D1 pair is expected to relax by internal conversion into this charge separated state. The absorption spectrum of Chl D1 Pheo pair is plotted in Figure . It covers almost the entire visible spectrum with the highest absorption at the low energy end. The pair can thus act as a light absorber itself, e.g. via S 2 , and then relax into the charge separated state S 1 .