Über „Orthoindate”︁ der Alkalimetalle: Zur Kenntnis von K5[InO4]

A New ?Orthoindate”? of an Alkali Metal: K₅[InO₄] Hitherto unknown K₅[InO₄] was prepared by heating intimate mixtures of K₂O, In₂O₃ and elementar In (molar ratio 10.0 : 1.0 : 4.0) in closed Ni-cylinders (30 days, 500°C) in form of pale red, nearly colourless, transparent, single crystals. Same crystals were obtained by heating mixtures of K₂O, CdO and elementar In (molar ratio 3.1 : 1.0 : 1.0) in closed Ag-cylinders (30 days, 450°C), too. In this case we also found yellow-brown crystals of K₁₄[In₄O₁₃] [1]. Structure determination by four circle diffractometer data (MoKα, 15279 out 17454 I_o(hkl), R = 5.60%, R_w = 5.25%). Space group P1 with a = 1827.9 pm; b = 1694.4 pm; c = 1329.4 pm; α = 113.3°; β = 111.4°; γ = 105.2°; Z = 16. Characteristic feature of the structure are isolated [InO₄]^5?-tetraeder. The Madelung Part of Lattice Energy, MAPLE, the Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN, and Charge Distribution, VADI, are calculated.