However, in this case, there are also higher relative errors throughout the POPC lipid bilayer, as seen in the lower part of Figure . It is also reflected in the MAEs and MAPEs shown in Table . The difference between the MAE of the outer and inner parts is smaller than for the other systems. Moreover, the MAPE of the inner part is comparably high due to the high MAPE in the induced dipoles on the lipids (37 %) and NRs (59 %). This behavior can be explained by the fact that the lipids and NRs are highly polarizable and thus more easily affected by the unphysical polarization at the outer boundary. Indeed, examining the errors in the lipids in more detail, we find that the higher relative errors are mainly in the lipid tails, while the errors are lower in the hydrophilic lipid heads (see upper right part of Fig. ). This system demonstrates clearly that the unphysical polarization at the outer boundary can propagate inwards and result in substantial errors at the center of the simulation box and potentially affect the properties of the quantum subsystem.