for 1PA strengths and roughly 20-30% for 2PA strengths. The convergence with respect to the cutoff distance is not always smooth (see, e.g., Figure ) indicating that some key amino-acid residues require a high-accuracy potential. and systems. This corresponds to around 50% of the amino acids for the systems investigated here. The cutoff distance can be further lowered to 8 Å, if a lower accuracy is acceptable (< 10%), thus cutting the cost associated with the calculation of the embedding potential by roughly 70%. It is also entirely viable to use a pure CP 3 description which would altogether remove the computational cost associated with the embedding potential. This can yield relatively large errors, especially for 2PA strength as discussed above, but for the other properties, the relative error remains below 10%. The conventional cutoff approach (i.e., where the M2P2 potential is used within a cutoff distance and everything else is neglected) requires much longer cutoffs to reach the same accuracy as the mixed M2P2/CP 3 with short cutoffs. To obtain relative errors below 5% for all properties, a cutoff of 34, 36, and 32 Å is required for the GFP, C1C2, and dodecin systems, respectively. It is noteworthy that almost the entire protein is included at these cutoff distances. In fact, the entire system is included at cutoff distances of 38, 42, and 40 Å for GFP, C1C2, and dodecin, respectively.