Four-and five-body terms computed using PBE also show a systematic negative and positive bias, respectively, indicating exaggerated magnitude for the higherorder n-body corrections. No such systematic error is observed in the HF results, where the n = 4 and n = 5 histograms are much more symmetric about zero. Assuming oscillating errors in the total energy, consistent with the data in Fig. , then for MBE(n) to converge it must be the case that