CaF2 (Fluorite) has an arrangement where
the fluorides are 4 coordinate and the Calcium is eight coordinate.
If the cations have CN=4 and the anions have CN=8 this is described as an
antifluorite structure, examples include Li2O and Na2O.
Generally, if the radius ratio r-/r+ exceeds ~1.37 then a
rutile rather than fluorite structure is favoured.
Complexes that adapt this structure include..
CdF2, HgF2, SrF2, PbF2, BaF2 and HfO2.
Copyright © 2006-2014 by Robert John Lancashire, all rights reserved.Created and maintained by Prof. Robert J. Lancashire,