Der Übergang vom „geordneten”︁ Anti-PbCl2-Gitter zum Anti-PbFCl-Gitter: Ternäre Phasen ABX der Erdalkalimetalle mit Elementen der 4. Hauptgruppe (A = Ca,Sr, Ba; B = Mg; X = Si,Ge, Sn,Pb)

The transition of the “ordered” anti-PbCl₂ lattice in the anti-PbFCl lattice: The ternary phases ABX of the alkaline earths with main group IV elements (A = Ca, Sr, Ba; B = Mg; X = Si, Ge, Sn, Pb) The compounds CaMgX, SrMgX and BaMgX (X = Si, Ge, Sn, Pb) were synthesized and their structures determined. CaMgX and SrMgX crystallize in the “ordered” Anti-PbCl₂-type and are therefore related to the binary compounds Ca₂X(X = Si, Ge, Sn, Pb), which form the Anti-PbCl₂-type too. The phases BaMgX build up the Anti-PbFCl-structure. The relations of these two different structures are discussed in respect to the radii of the components.