Liquid butanol with four distinct CG mappings was used as a small molecule system to compare the IBI, ML, and TL models (Fig. ). Butanol was selected as a simple molecule with anisotropic interactions. These mappings were selected since they displayed slightly reduced force errors over other mapping operators in our previous study. A liquid simulation of 7-mers of poly-ethelyene glycol (PEG) was used as a benchmark system for macromolecules (Fig. ). The PEG polymer was coarse-grained with 4 CH2-O-CH2 beads and 2 end beads of OH-CH2-O-CH2-CH2. This mapping is comparable to typically used resolutions of 3-5 heavy atoms per bead. All the MD simulations for the target atomistic system, the IBI training, as well as simulations for performance evaluation of coarse-grained models were performed using LAMMPS at 298K and 1 atm pressure (Section S1).