Naturally occurring CaF 2 is the principal source of hydrogen fluoride, a commodity chemical used to produce a wide range of materials.Ĭalcium fluoride in the fluorite state is of significant commercial importance as a fluoride source. High purity CaF 2 is produced by treating calcium carbonate with hydrofluoric acid: CaCO 3 + 2 HF → CaF 2 + CO 2 + H 2O Applications Thus, little motivation exists for the industrial production of CaF 2. The mineral fluorite is abundant, widespread, and mainly of interest as a precursor to HF. It has been proposed that this is due to the fluoride ligands interacting with the electron core or the d-subshell of the calcium atom. The gas phase is noteworthy for failing the predictions of VSEPR theory the CaF 2 molecule is not linear like MgF 2, but bent with a bond angle of approximately 145° the strontium and barium dihalides also have a bent geometry.
In the corresponding anti-structure, called the antifluorite structure, anions and cations are swapped, such as Be 2C. The same crystal structure is found in numerous ionic compounds with formula AB 2, such as CeO 2, cubic ZrO 2, UO 2, ThO 2, and PuO 2. Although perfectly packed crystalline samples are colorless, the mineral is often deeply colored due to the presence of F-centers. Each F − centre is coordinated to four Ca 2+ centres in the shape of a tetrahedron. Ĭa 2+ centres are eight-coordinate, being centered in a cube of eight F − centres.
The second origin is often used when visualising point defects entered on the cation. Unit cell of CaF 2, known as fluorite structure, from two equivalent perspectives. The compound crystallizes in a cubic motif called the fluorite structure.
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