V, E and R are the atom, bond and ring set, respectively. Atom, bond, and ring features are specified by h V (atom type, chirality, degree number, etc.), h E (bond type, stereochemistry, conjugated type) and h R (a concatenation of atom and bond features that are involved in the rings). For NeuralFP, only G = (V, E) and atom features h V are utilized in the iterative message passing (graph convolution) step, where involved features are updated by message-passing layers that merge information from the neighborhood of a central node.