Two new isotypic d/f-heterometallic purely inorganic cationic materials, [Ag2M(Te2O5)(2)]SO4 (M = Ce-IV or Th-IV), were synthesized using the metal oxides (MO2 and TeO2), silver nitrate, and sulfuric acid under mild hydrothermal conditions. The prepared materials were characterized via single-crystal X-ray diffraction, which revealed that the materials possess a 3D framework of corner-sharing Te2O52- units. The tellurite framework creates four unique pores, three of which are occupied by the M-IV and Ag-I metal centers. The tellurite network, metal coordination, and total charge yield a cationic framework, which is charge-balanced by electrostatically bound sulfate anions residing in the largest of the four framework pores. These materials also possess Ag-I in a ligand-imposed linear geometry.