While with AIMNet2 we employ physics-based calculations like QM by searching for conformers and then computing the RSE as the energy difference of a homodesmotic reaction, the GNN adopts a purely data-driven approach using only 2D information (Figure ). Each molecule is represented as a graph, with atoms as graph nodes and chemical bonds as graph edges. The GNN comprises 2 layers of message-passing layers and 6 residual modules . Following these, there are two output layers that predict the ring size and RSE, respectively. Predicting ring size serves