A similar picture is observed for the NR-in-BLG system (Fig. ). Here the MAE for the outer part of the simulation box is 0.06 D and only 0.01 D for the inner part. Just as for the PNP1 system, the errors in the induced dipoles on the water molecules decrease toward the center of the simulation box. Interestingly, however, we observe higher relative errors in the BLG protein despite it being at the center of the simulation box (see lower right part of Fig. ). The MAPE for the protein is thus 9 % compared to 3 % for the entire inner part, which includes the protein and water. The MAE in the induced dipoles on the protein is small (0.01 D) compared to the outer part (0.06 D). Nonetheless, this shows that the errors caused by the unphysical polarization at the outer boundary can result in errors at the center of the simulation box. This is most likely connected to the fact that some parts of the protein are more polarizable than water. In the NR-in-POPC system (Fig. ), we again observe high errors at the outer boundary.