where E(AA -solv ) is the energy of the singly-reduced solvated species. These calculations refer to adiabatic redox processes, ignoring zero-point vibrational energies, but including a solvation energy term. All other thermochemistry contributions were ignored; these are expected to contribute energies generally not exceeding 0.1 eV when treating organic molecules in water , for which mean error estimates are not expected to exceed 0.3 eV at a comparable level of theory . For each AA, the predominant species present at pH 7 was considered, so that for 16 AAs an uncharged singlet state and the doublets of the corresponding anion and cation were considered, as implied by Eqs. ( )-( ). The singlet state species of lysine and arginine were protonated, and those of aspartic and glutamic acids were deprotonated.