Germanium difluoride (GeF<sub>2</sub>) is a chemical compound of germanium and fluorine. It is a white solid with a melting point of 110 ðC, and can be produced by reacting germanium tetrafluoride with germanium powder at 150âÂÂ300 ðC.
Germanium difluoride forms orthorhombic crystals with a space group P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub> (No. 19), Pearson symbol oP12, and lattice constants a = 0.4682 nm, b = 0.5178 nm, c = 0.8312 nm, Z = 4 (four structure units per unit cell). Its crystal structure is characterized by strong polymeric chains composed by GeF<sub>3</sub> pyramids. One of the fluorine atom in the pyramid is shared by two neighboring chains, providing a weak link between them. Another, less common crystal form of GeF<sub>2</sub> has tetragonal symmetry with a space group P4<sub>1</sub>2<sub>1</sub>2 (No. 92), Pearson symbol tP12, and lattice constants a = 0.487 nm, b = 0.6963 nm, c = 0.858 nm.