To validate the order ten ECP variant of our model, for high interaction energies, a set of different dimer complexes of two identical molecules, none of them being part of the calibration dataset, is analyzed (Figure ). Specifically, the complexes H 2 + H 2 , N 2 + N 2 , O 2 + O 2 , and CO 2 + CO 2 are considered, due to these being small enough to allow high accuracy ab initio calculations to be made, and since the molecules that are part of these complexes are of considerable interest in various other scientific fields such as biology, atmospheric sciences, Mulliken Charges CCSD(T)/CEP-31G Figure . Comparison between modeled partial charges for the full electron and ECP variants of our model and their respective ideal, ab intio calculated, Mulliken charges. The comparison includes all water dimer configurations used in calibrating both model variants. Orange data points represent all the partial charges extracted from configurations with ab initio calculated interaction energies surpassing 50 kJ/mol, while green data points correspond to configurations exhibiting interaction energies below this threshold. For clarity, the distribution of the data points along each axis are also plotted above and to the right of the plot panels. material science, etc. Refer to Figures S2 through S5 of the supplementary material for diagrams illustrating the geometric configuration of the dimer complexes used in Figure . For the ab initio calculations of the interacting dimer complexes, all the systems are assumed to be in their singlet states, except for all the O 2 + O 2 complexes where the systems are assumed to be quintets. While these results are not shown in this manuscript, identical results are obtained for the same geometric configurations of O 2 + O 2 complexes in their triplet states if the interatomic separation between the dimers is kept at not too long distances. For larger separations the ab initio calculations fail to converge with equal or less than 200 SCF iterations, possibly due to basis-set limitations.