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CaF2 is Fluorite structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ca2+ is bonded in a body-centered cubic geometry to eight equivalent F1- atoms. All Ca–F bond lengths are 2.39 Å. F1- is bonded to four equivalent Ca2+ atoms to form a mixture of edge and corner-sharing FCa4 tetrahedra.
CaF2 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. Ca2+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of Ca–F bond distances ranging from 2.22–2.44 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted rectangular see-saw-like geometry to four equivalent Ca2+ atoms. In the second F1- site, F1- is bonded in a distorted T-shaped geometry to three equivalent Ca2+ atoms.
CaF is Wurtzite structured and crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Ca is bonded to four equivalent F atoms to form corner-sharing CaF4 tetrahedra. All Ca–F bond lengths are 2.42 Å. F is bonded to four equivalent Ca atoms to form corner-sharing FCa4 tetrahedra.
CaF3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ca is bonded to twelve F atoms to form a mixture of face, edge, and corner-sharing CaF12 cuboctahedra. There are eight shorter (2.49 Å) and four longer (2.69 Å) Ca–F bond lengths. There are two inequivalent F sites. In the first F site, F is bonded to four equivalent Ca atoms to form a mixture of edge and corner-sharing FCa4 tetrahedra. In the second F site, F is bonded in a square co-planar geometry to four equivalent Ca atoms.