The CGMD models were evaluated based on their ability to reproduce various on-target and off-target properties from the reference atomistic simulations. Here, on-target refers to properties that the models were directly trained to reproduce. In the case of the Delta-models this includes the radial distribution functions (RDF), atomistic forces, and possibly the pressure. Off-target properties include the molecular enthalpy of vaporization (H v ), self-diffusion coefficient, and atomistic forces in the gas phase (i.e., configurations that were not directly trained on). The errors for RDF, pressure, H v and diffusivity are normalized with respect to the atomistic values, whereas the force error is reported as the net RMSE over all configurations and beads (i.e., the same as the objective function for DeePCG). The procedures for simulating these quantities and the error expressions are described in Section S5.