Structure of (Ni,Mg)10Ge3O16

(Ni0.45Mg0.55)10Ge3O16, Mr = 871.7, trigonal, Ranti 3, r = 10.1250(5) A, a = 33.790(1)0 [a = 5.8850(4), c = 28.6135(12) A, hexagonal cell], V = 286.1 A3, Z=1, Dx = 5.060 g cm-3, λ(Mo Kα) = 0.71069 A, μ = 152.39 cm-1, F(000) = 416, room temperature, final R = 0.014 for 1572 unique reflections. The structure consists of alternate {111} layers of spinel-like and rock-salt-like structures stacked in the ratio 3:1 in the direction of chex. Structural accommodation between the two structural units is made in the layer of O(3) atoms. Otherwise, coordination polyhedra are fairly regular and cation-oxygen distances correspond to ideal values. Ni is weakly partitioned into the rock-salt-like layers. (orig.)