Single crystals of fully dehydrated and fully Ca2+-exchanged zeolites A (|Ca6|[Sii2Ali2O48]-LTA) and X (|Ca46| [SiiooAl92O384]-FAU) were brought into contact with Te in fine pyrex capillaries at 623 K and 673 K, respectively, for 5 days. Crystal structures of Te-sorbed Ca2+-exchanged zeolites A and X have been determined by single-crystal X-ray diffraction techniques at 294 K in the cubic space group Pm 3 m (a = 12.288(2) A) and Fd 3 (a = 25.012(1) A), respectively. The crystal structures of pale red-brown |Ca6Tes|[Si12Al12O48]-LTA and black coloured |Ca46Te8| [Si1ooAl92O384]-FAU have been refined to the final error indices of R1/WR2 = 0.1096/0.2768 and R1/WR2 = 0.1054/ 0.2979 with 204 and 282 reflections for which Fo > 4°(F。)，respectively. In the structure of |Ca6Tes|[Si12Al12O48]-LTA, 6 Ca2+ ions per unit cell were found at one crystallographic positions, on 3-fold axes equipoints of opposite 6-rings. In |Ca46Te8|[Si10()Al92O384]-FAU, 46 Ca2+ ions per unit cell were found at four crystallographically distinct positions: 3 Ca2+ ions at Ca(1) fill the 16 equivalent positions of site I, 21 Ca2+ ions at Ca(2) fill the 32 equivalent positions of site I'，10 and 12 Ca2+ ions at Ca(3) and Ca(4), respectively, fill the 32 equivalent positions of site II. The Te clusters are stabilized by interaction with cations and framework oxygen. In sodalite units, Te-Te distances of 2.86(10) and 2.69(4) A in zeolites A and X, respectively exhibited strong covalent properties due to their interaction with Ca2+ ions. On the other hand, in large cavity and supercage, those of 2.99(3) and 2.76(11) A in zeolites A and X, respectively, showed ionic properties because alternative ionic interaction was formed through framework oxygen at one end and Ca2+ cations at the other end.

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