REINVENT includes two non-standard elements that modify the RL process and are used here without modification. Firstly, REINENT uses a memory mechanism called a "diversity filter" to encourage exploration of the chemical space. A record of molecules with scores greater than a user defined minimum is maintained during RL and scores of new molecules in excess of "bucket size" that are too similar to existing ideas are set to zero. Here, we use identical Murcko scaffolds , a bucket size 100 and a minimum score 0.2.