While the accuracy of parameters is important by itself, an even more important gauge is the accuracy of interaction energy, which eventually determines the behavior of the MD simulation. To evaluate the accuracy of our long-range force field, we constructed a dataset using SAPT, which encompasses all combinations of dimers formed by fragments with 1-8 heavy atoms. Dimer scan is performed to sample the conformations over a range of distances from kcal/mol and 0.061 kcal/mol, respectively. The error from the Hirshfeld-E3NN model is slightly lower, in consistent with the fact that the Hirshfeld multipoles can be fitted slightly better. Figure ) demonstrate the accuracies of the polarization energy and dispersion energy, respectively. Only BS-ISA/ISA-Pol results are shown since at present, the Hirshfeld method cannot be used as an alternative to the BS-ISA in the ISA-Pol algorithm to provide atomic response parameters. The prediction accuracy of our force field for polarization and dispersion energy is lower than that for electrostatic energy. Some data points deviate from the diagonal line in Figure (c) and the R 2 for polarization is 0.957. This may due to the approximation of the atomic polarizability as isotropic and the truncation at the dipole level.