To further validate the transferability of the model with respect to system size, we also test the performance of different models on the most stable hexamer and 12mer water clusters, the structures of which are given in Figure . The predicted interaction energies are plotted along the side with the CCSD(T) reference and the MB-pol results for comparison. In our work, we find that quite often, the model performance on these stable clusters do not correlate with their performance on the octamers tests that are sampled from the bulk PIMD trajectory. Furthermore, we cannot obtain a reasonable agreement in the hexamer/12mer tests without adding in new training data sampled from small cluster PIMD trajectories. , as the long-range terms and isotropic short-range terms are gradually separated from the ML potential, it shows a general trend of improvement. Again, the pure EANN model behaves the worst, and the separation of the electrostatics term alone does not help significantly (both models are shown in the insets of Figure ).