In the first fixed policy, all possible actions are chosen with equal probability (Uniform). The other fixed policy was hand-tuned in in such a manner that the code efficiently locates the crystal structure of Y2Ti2O7 with a limit of 150 atoms per unit cell. This policy is the default search policy in the FUSE code (Original, Fig. ). Thus the comparison of three policies, Uniform, Original and the dynamic RL-CSP policy (RL-CSP) is made by computing the structures of materials from the Y 3+ -Sr 2+ -Ti 4+ -O 2-phase field defined above.