A NEW ORTHOINDATE OF AN ALKALI-METAL - K5 [INO4] .1.

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-degrees-C) in form of pale red, nearly col ourless, 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-degrees-C), too. In this ca se we also found yellow-brown crystals of K14[In4O13] [1]. Structure d etermination by four circle diffractometer data (MoKalpha, 15279 out 1 7454 I(o)(hkl), R = 5.60%, R(w) = 5.25%). Space group P1BAR with a = 1 827.9 pm; b = 1 694.4 pm; c = 1329.4 pm; alpha = 113.3-degrees; beta = 111.4-degrees; gamma = 105.2-degrees; Z = 16. Characteristic feature of the structure are isolated [InO4]5--tetraeder. The Madelung Part o f Lattice Energy, MAPLE, the Mean Fictive Ionic Radii, ME-FIR, Effecti ve Coordination Numbers, ECoN, and Charge Distribution, VADI, are calc ulated.