It has to be noted that such calculations necessarily include the virtual orbitals formally located in the environment region (unless truncation schemes are applied), which helps to describe certain types of environment response effects (outgoing CT), but at the same time adds to the computational burden. For smaller system sizes, where full EOM-CCSD calculations could still be conducted, the error of the PbE-EOM-CCSD calculations was within 0.01 eV. Another detailed analysis of PbE-EOM-CCSD results including excitation energies, electronic resonances, but also ionization and electron attachment processes, has been presented by Parravicini and Jagau .