Upon analyzing the Mulliken charges derived from the reference ab initio dataset and the corresponding modeled partial charges in both our full electron and ECP fitted cases, along an O • • • H distance coordinate, a noticeable decline in accuracy is observed when interatomic distances become too short. Nevertheless, both variants of our model demonstrate commendable accuracy in comparison to their target ab initio data, with the ECP variant exhibiting a slightly superior performance (refer to the left panels of Figure ). Specifically, when the distance between the hydrogen atom (labeled as 2) and the oxygen atom (labeled as 4) is reduced to 2.535 Å, both our ECP and full electron models exhibit a discernible deviation from their target Mulliken charge for the oxygen atom labeled with the number 1. The right panels of Figure provide an identical examination of Mulliken charges along the same O • • • O distance coordinate as shown in right panel of Figure . In this repulsive distance coordinate, both models demonstrate even greater accuracy compared to the O • • • H distance coordinate, successfully reproducing the ab initio calculated partial charges within a small margin of error. Once again, the ECP variant exhibits a slight edge in accuracy.