Our goal is to obtain the DFT ground state energy of an adsorbed arbitrary molecule, employing the simplest graph representation. To this end, we followed the procedure illustrated in Figure . The workflow consists of the following steps: (1) generation and curation of the "functional groups" FGdataset, consisting of organic molecules with representative functional groups adsorbed on close-packed metal surfaces to sample the common chemical To build the graph to be employed as input of the GNN, we started from 3D-atomic coordinates. For gas phase molecules, each atom is treated as a node storing its nature (element), while the bonds are taken as the edges.