Fig. shows the errors of the db-MBE(2) and db-MBE(3) obtained in this case. The results with OO-CCD densities and with HF densities are remarkably close, with differences below 1 kJ/mol. In fact, the errors are slightly reduced when using the HF densities, which is most likely due to error cancelation. In conclusion, HF densities seem to be a reasonable approximation of the CCSD(T) densities in the context of the db-MBE.