From the W4-11 database , we select for correlation energy testing the following subset of 96 closedshell systems that are not included in our training set from above: AlF 3 , S The BH test data is taken from Ref. 19 and employed similar to the training reference correlation data points of the stretched diatomic systems. Lastly, the interaction energies of the formic acid dimer, and other systems of Fig. from the S22x5 database , are calculated analogously to RG18 at the CCSD(T)/CBS level of theory and are taken from the original dataset .