FUSE was benchmarked on compositions from the Y 3+ -Sr 2+ -Ti 4+ -O 2-phase field, containing the following known compounds: TiO2, SrO, Sr2TiO4, Sr3Ti2O7, SrTiO3, Sr4Ti3O10, Y2TiO5, Y2Ti2O7, SrY2O4, Y2O3 (other compounds are reported, but adopt modified versions of the structures of these ten compounds) . In preliminary testing, we found that TiO2, SrO, Sr2TiO4, Sr3Ti2O7, and SrTiO3 are trivial for FUSE with the global minimum being found within ten BH steps, and so do not use these compositions in our experiments. We test RL-CSP embedded into FUSE on the remaining five compositions Sr4Ti3O10, Y2TiO5, Y2Ti2O7, SrY2O4, Y2O3, for which highly probable global minimum structures are reported in . For the compositions: Sr4Ti3O10, Y2TiO5, Y2Ti2O7, SrY2O4, we allow FUSE to use up to 50 atoms per unit cell and for Y2O3 we allow 80, ensuring that for each composition it is possible to generate the observed global minimum structure. We contrast these results with those obtained with FUSE using two fixed policies. contains the numbers between the first and third quartiles of the data separated by the median, the maximum and minimum numbers of steps are the highest and lowest ticks ("whiskers") respectively. Given a composition, the green (RL-CSP) box is typically shorter and placed lower than orange (Uniform) reflecting the advantage of RL-CSP over the Uniform policy that it starts with.