Materials Data on CaF2 by Materials Project
CaF2 is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ca2+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Ca–F bond distances ranging from 2.33–2.84 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to four equivalent Ca2+ atoms to form a mixture of corner and edge-sharing FCa4 tetrahedra. In the second F1- site, F1- is bonded in a 3-coordinate geometry to five equivalent Ca2+ atoms.