Zur Kenntnis der Oxoberyllate der Alkalimetalle [1, 2]

On Oxoberyllates of the Alkali-Metals The existence of the phases K₂Be₂O₃ (2 forms), K₄BeO₃, Rb₂Be₃O₄, Rb₂Be₂O₃,Rb₄BeO₃, Cs₂Be₃O₄ and Cs₂BeO₂ is proved by powder-datas according to GUINIER -SIMON . In single crystal form we obtained Li₄BeO₃ a = 5.49; b = 9.53; c = 4.93 Å; a = 114.₁; ß = 105.₀; γ = 106.₆°; triclinic], Na₂Be₂O₃ ;a = 6.32; b = 8.53; c = 2.71 Å; α = 107.₇; ß = 105.₅; γ = 78.₄°; triclinic], Na₆Be₂O₅ a = 5.67₂; c = 10.2₁ Å; tetragonal] as also K₂BeO₂ a = 7.09₈; b = 10.57₇; c = 5.70₆ Å; γ = 131.₃°; monoclinic] and Rb₂BeO₂ a = 7.46₃; b = 11.17₀; c = 5.88₁ Å; γ = 131.₈°; monoclinic].