Das erste Oxothallat(III) vom Formeltyp AA4′[MO4]: CsK4[TlO4]

The First Oxothallate(III) with the Formula Type AA₄′MO₄]: CsK₄TlO₄] For the first time CsK₄TlO₄] was obtained by heating intimate mixtures of K₂O, CdO and CsTl (molar ratio 3.1:1.0:1.0) in closed Ag-cylinders (25 days, 450°C) in form of yellow, transparent single crystals. The structure determination by four circle diffractometer data (MoKα, 1922 out of 2 094 I_o(hkl), R = 2.98, R_w = 2.49) confirms the space group Pbca with lattice constants a = 1 192.1 pm; b = 685.7 pm; c = 2 143.5 pm; Z = 8. The structure is isotypic with Na₅GaO₄]. The Madelung Part of Lattice Energy, MAPLE, the Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN, and Charge Distribution, CHARDI, are calculated.