Fluorine ionic crystal radius

Shannon and Prewitt base their effective ionic radii on the assumption that the ionic radius of O2- (CN 6) is 140 pm and that of F (CN 6) is 133 pm. Also taken into consideration is the coordination number (CN) and electronic spin state (HS and LS, high spin and low spin) of first-row transition metal ions. These radii are empirical and include effects of covalence in specific metal-oxygen or metal-fluorine bonds. Older crystal ionic radii were based on the radius of F (CN 6) equal to 119 pm these radii are 14-18 percent larger than the effective ionic radii. 

Disilver fluoride is a bronze-colored compound with a greenish cast when observed in bulk. It is an excellent electrical conductor. Crystal-structure determination3 shows the complete absence of elemental silver and silver(I) fluoride in the pure material and reveals the presence of successive layers of silver, silver, and fluorine in the lattice. The silver-silver distance is 2.86 A. (nearly twice the metallic radius of 1.53 A.), and the silver-fluorine distance is 2.46 A. [as in ionic silver(I) fluoride]. The compound is regarded as being intermediate in structure between a metal and a salt.4... 

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