FDE-ET was originally formulated for charge-migration processes such as hole transfer reactions, for which a detailed benchmark was presented in Ref. . Later studies addressed the role of substituents and central metal on hole transfer in porphyrin dyads . The impact of environmental effects on hole transfer couplings in DNA oligomers was studied in Ref. , demonstrating the power of this approach for biological systems. An application along similar lines for ET in the cryptochrome protein from the green alga