Das erste Oxomanganat(II): Na14Mn2O9 = Nal4[MnO14]2O

The First Oxomanganate(II): Na₁₄Mn₂O₉ = Na₁₄MnO₄]₂O Na₁₄Mn₂O₉ crystallizes trigonal, space group P3 , a = b = 6.66₉, c = 9.35₃ Å. The crystal structure han been refined by diffractometer data (1124 undependent reflections) to R = 0.050. Mn²⁺ is surrounded tetrahedrally (Mn? O = 2.09 Å). Effective Coordination Numbers, ECoN, and the Madelung Part of Lattice Energy, MAPLE, are calculated. Na₁₄Mn₂O₉ represents the most kation-rich ternary oxid of the alkali metals.