Ketten aus Ringen: K5{Li[Ge2O7]} — das erste „Litho-Digermanat”︁

Chains consisting of Rings: K₅{LiGe₂O₇]} — the First ‘Litho-Digermanate’ By heating of a well-ground mixture of the binary oxides KO_0.55, Li₂O and GeO₂ (K: Li: Ge = 6.1 : 2.2 : 2; Ni-tube; 600°C; 49 d) we obtained for the first time single crystals of K₅{LiGe₂O₇]}. This ‘lithodigermanate’ represents a completely new type of structure: monoclinic, space group P2₁/c, a = 624.9(2) pm, b = 1586.6(8) pm; c = 1058.3(6) pm and β = 109.38(4)°; Guinier-Simon data, Z = 4. The structure was solved by four-circle diffractometer data Siemens AED II, Mo? Kα ; 2872 I_o(hkl); R = 4.5%, R_w = 3.3%], parameters see text. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these calculated via Mean Fictive Ionic Radii, MEFIR, as well as charge distribution CHARDI, are calculated and discussed.