Zum Aufbau von RbNa5Be8O11

On RbNa₅Be₈O₁₁ For the first time RbNa₅Be₈O₁₁ was obtained by annealing intimate mixtures of the binary oxides (Rb:Na:Be = 1.1:5.5:8, Ni-cylinder, 650°C, 21d). The compound crystallizes triclinic (P 1 ) with a = 1 063.4 pm, b = 645.6 pm, c = 948.8 pm, α = 110.2º, β = 114.9º, γ = 90.8º, Z = 2. The crystal structure was solved by four-circle-diffractometer data [Siemens AED2, 3099 I₀ (hkl), R = 5.1%, R_w = 3.8%]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, are calculated.