For the conventional MFCC method with ACE-NME caps the error of 648 kJ/mol amounts to ca. 8.5 kJ/mol per amino acid fragment. Despite differences in the implementation of the fragmentation scheme and the employed quantum-chemical methods, this is comparable to previous studies that report total energies. For instance, in Ref. an error in the total energies of ca. 22.9 kJ/mol per fragment was found for the small protein alphaconotoxin with 13 amino acids. For MFCC-MBE(2), the error in our ubiquitin test case amounts to only 0.74 kJ/mol per amino acid, while in Ref. an error of 0.9 kJ/mol per amino acid was found for alpha-conotoxin using the similar MFHC-[Hier2] scheme.