MOF-5 (IRMOF-1) Zn4O framework structure without organic linkers. Space group Fm-3m (225), a=25.832 Å. 8 Zn4O clusters at 8c positions with 32 Zn at 32f. Built from crystallographic data in Li & Ahlquist, npj Comput. Mater. (2026). For MLIP symmetry preservation testing on open-framework structures.