Fig. 4. PXRD patterns collected autonomously for ROY polymorphs. (A) Comparison of the diffraction pattern for ROY processed using the robotic workflow (sample 1 in (C) and (D)), as compared with the simulated PXRD pattern for the published monoclinic yellow (Y) polymorph (CSD reference code QAXMEH); (B) PXRD patterns for ROY processed using the autonomous robotic workflow (sample 4 in (C) and (D)), as compared with the simulated patterns for two published forms: the monoclinic Y polymorph (QAXMEH) and the monoclinic orange needle (ON) polymorph (QAXMEH01), suggesting that a phase mixture is formed under these conditions; (C) photograph of ROY processed using the robotic workflow at various concentrations and solvent ratios (see ESI, Table S1,† for crystallization conditions); (D) diffraction patterns for the ROY samples shown in (C).