In the calculations with hydrogen caps, the H-MFCC and H-MFCC-MBE(2)-ff methods are implemented as described in Section 2.1, and the H-MFCC-MBE(2) method is implemented as described in Section 2.2, without modifications for the treatment of 1- with Amsterdam Density Functional (ADF) program in the Amsterdam Modeling Suite (AMS) with the BP86 exchange-correlation functional and a DZP basis set . Note that we did not include a dispersion correction, as those commonly applied in combination with DFT only depend on the molecule coordinates can thus be applied consistently on top of both supermolecular and fragmentation calculations. Therefore, the neglect of a dispersion correction does not alter the comparison of the total energies.