Surprisingly, the overall decoherence in thymine is the fastest, even when it is the smallest and least polar molecule in the set and admits fewer possible hydrogenbond interactions with the solvent. This can be rationalized by noting that the electronic excitation is localized in the thymine ring (see Fig. ) and thus interactions with the solvent with atoms in this area are expected to have the strongest impact on the decoherence. In fact, in T the N-H termination in the ring, which is absent in T+S and T+S+P, strongly interacts with water through hydrogen bonding , accelerating the overall decoherence.