To assess the accuracy of the considered energy-based and density-based fragmentation schemes across different regions of the potential energy surface, we consider relative energies of three different sets of conformers, specifically (Ala) 10 as α-helix, (Ala) 11 as a turn (modeling a β-sheet structure), and (Ala) 10 as a β-strand. For each set, 11 (for the αhelix and the turn) or 9 (for the β-strand) snapshots extracted from molecular dynamics simulations with a classical force field (see Refs. and for details) have been used. errors that vary widely across the different conformers. With eb-MFCC-MBE(2) we find absolute errors between 35 and 65 kJ/mol. However, the inclusion of the density-based correction in the db-MFCC-MBE(2) scheme is able to reduce the error consistently, with the largest errors (9.9 and 11.2 kJ/mol) found for conformers 09 and 10.