The electronic densities of all elements in the first three rows of the periodic table are well reproduced by three Gaussian functions, albeit the approximation of the electronic densities of H and He is noticeably rougher compared to the other atoms. This can be seen in Figure for He and Li atoms. This is unsurprising since the full electron density of these two elements is a sum of two 1s type orbitals, due to the basis set used. This is no longer a problem for the other elements since their 2s atomic orbitals are already much smoother. The coefficients for the first three rows of the periodic table can be found in the supplementary material. For the energies, the corrected model of order 10 can reproduce the ab initio data with a fair degree of accuracy, outperforming well established force fields (Figure ). This comparison is subjective since it emphasizes regions where the interaction is highly repulsive. Nonetheless, it is our aim to develop a model where these regions are reproduced since they can be of particular interest for simulations of systems at high temperatures or kinetic energies. Fig. . Comparison between the interaction energies obtained from CCSD(T)/cc-pVTZ level of theory (singlets) against the results from our corrected model (order 10) and three established force field models. The data points displayed are the same that have been used to fit the model. Interestingly, only MMFF94S stays qualitatively correct at high energies although not as accurately as our model. Inspecting the geometries one sees that in the water dimer for ∆L O-O < 3 Å, both GAFF and TIP3P fail to reproduce the interaction energy, whereas both our model and MMFF94S still remain accurate even when the interatomic distance is 2 Å, and UFF fails to reproduce the ab initio calculated water dimer energies in the entire range of Figure . Fig. . Interaction energy of a water dimer in the O -O reaction coordinate shown in Figure (θ = π) obtained from ab initio calculations (singlets) using CCSD(T)/cc-pVTZ level of theory and several force field models including ours with an order ten correction.