We sublimed the P212121 α-polymorph of TPhP at 425 °C, which is the same polymorph as that reported from crystallization from CH2Cl2/hexane. The crystal packing in TPhP-α closely matches a predicted structure from the computed crystal structure landscape, 2 (Figure ). The geometric agreement between these structures is excellent (SI, Figure ), but this structure is predicted to lie above the global minimum energy structure. The energetic ranking of this structure might reflect limitations of the force field and rigid-molecule approach adopted in the CSP, but it might also indicate that more thermodynamically stable crystal structures of TPhP exist.