Stoichiometry of Fluorite 4 Lattice Cations:8 Tetrahedral Anions 1:2 Stoichiometry (CaF2,SrCl2,HgF2) XIll-5Stoichiometry of Fluorite 4 Lattice Cations: 8 Tetrahedral Anions 1:2 Stoichiometry (CaF2, SrCl2, HgF2) XIII-5