Preparation of input data. The molecules of the training dataset are represented in a feature map, which is the data format for input to VGAE. The graph structure representation of a molecule is to convert it into a vector, with atoms represented by nodes and bonds by edges. In the conversion of the molecules to vector representation, node features and edge features were computed using RDKit . Details of node and edge features are shown in Tables and, respectively. The features of the nodes were concatenated to create a feature map of the nodes.