The first approach continues to frame the problem as a double-ended search between reactants and products but utilises 2D graphs to represent molecules instead of 3D geometries. A generalisation of 2D graph-based approaches is given in Figure . This method was exemplified by Lemm et al. who addressed TS geometry prediction as part of a broader effort to predict equilibrium geometries and crystal structures. Their Graph to Structure (G2S) model employs KRR to predict the atomic positions of heavy atoms within a distance matrix. This matrix constructs a final 3D geometry using the DGSOL software 159 to create the heavy atom scaffold, along with a Lebedev sphere optimisation for adding hydrogen atoms. A reaction SMILES is used to create a 2D graphical representation of a molecule, which is fed into a neural network (NN) and used to predict the 3D coordinates of a TS geometry.