Double fluorite-type layers

The consideration of the coordination of calcium in the oxides characterized by double pyramidal copper layers shows that the CaOg cubes share their edges forming a single fluorite type layer (Fig. 28a). This suggests the possibility of replacing these single fluorite type layers by double or triple fluorite type layers (Fig. 28b). Indeed... 

Coexisting layer Other types types Mackinawite-like layer with/ without vacancies (vii) Fluorite-like layer (vii) Galena-like layer (v) 3 net (ii) 6 net (i) Valleriite- Double Octahedrtil like layer octahedral layer with/ (vi) layer (iv) without vacancies (iii)... 

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