Model Overview. Link-INVENT takes as input a pair of warheads, i.e., two molecular subunits with exit vectors defined, generates a linker, and returns the linked molecule in the SMILES format (Fig. ). The model is adapted from Lib-INVENT, our previously reported generative model for library design by Fialková et al. which in turn is based on work by Arús-Pous et al. Specifically, Link-INVENT features an encoder-decoder architecture consisting of identical RNNs with embedding size 256 and three hidden layers of 512 long short-term memory cells (LSTM). Data Preparation. The training data was generated from ChEMBL via the following steps 37 :