Fluorite type (CaF2) 5. 1.20 are shown the anions in a fcc unit cell with all Antifluorite type (Na2O) This lecture is very important from entrance point of view. Cations form the cubic close packing while anions fill all tetrahedral holes. La structure fluorine CaF 2 Modèles JMol : [ Rotation: Bouton gauche et bouger] - [ Zoom: roulette de la souris] - [ Options: Clic droit] Motif formulaire CaF 2 CONTROLS – Ca 2+ 8 (cubic) : F – 4 (tetrahedral) Ca 2+ with F – in all Td holes. In Fig. If the cations have CN=4 and the anions have CN=8 this is described as an antifluorite structure, examples include Li 2 O and Na 2 O. Home / Inorganic Chemistry / AB2 structures / CaF2 – Fluorite: Interactive 3D Structure. Polyhedra – Edge-sharing , edge-sharing . CaF2 (Fluorite) has an arrangement where the fluorides are 4 coordinate and the Calcium is eight coordinate. CaF 2 – Fluorite: Interactive 3D Structure. 1.17 Some important structure types a) Rock salt (NaCl), zinc blende or sphalerite (ZnS), fluorite (CaF2), antifluorite (Na2O) These structures are considered together because they all have ccp/fcc anions and differ only in the positions of the cations.