Two crystal structures of Ba²⁺- and Tl⁺-exchanged zeolite X, Ba₃₀Tl₃₂ Si₁₀₀Al₉₂O ₃₈₄ -FAU and Ba₁₃Tl₆₆ Si₁₀₀Al ₉₂O₃₈₄ -FAU

Two crystal structures of fully dehydrated Ba²⁺- and Tl ⁺-exchanged zeolite X, Ba₃₀Tl₃₂-X (a = 25.214(2) Å) and Ba₁₃Tl₆₆-X (a = 25.167(2) Å), have been determined by using single-crystal X-ray diffraction techniques in the cubic space group Fd3̄ at 21(1) °C. Their structures were refined to the final error indices R₁ = 0.053 and ωR₂ = 0.116 with 637 reflections and R₁ = 0.060 and ωR₂ = 0.126 with 628 reflections, for which Fo > 4σ(Fo). In the structure of Ba₃₀Tl₃₂-X, 30 Ba²⁺ ions were found at three crystallographic sites: 7 Ba²⁺ ions per unit cell occupy site I at the centers of the D6Rs, 3 Ba²⁺ ions occupy the 32-fold site I′ and the remaining 20 Ba²⁺ ions are at site II in the supercage. Thirty-two Tl⁺ ions were located at four crystallographic sites: 14 Tl⁺ ions occupy the 32-fold site I′ in the sodalite cavity opposite the D6Rs, 10 Tl⁺ ions occupy the 32-fold site II supercage and the remaining 8 Tl⁺ ions occupy two different III′ sites. In the structure of Ba₁₃Tl₆₆-X, 13 Ba²⁺ ions were found at three crystallographic sites: 1 at site I, 6 at site II and 6 at III′. Sixty-six Tl⁺ ions are found at four crystallographic sites: 31 at site I′, 26 at site II and the remaining 9 at two different III′ sites with occupancies of 3 and 6.