Ionic radii in crystals

Since an a priori definition of the effective region is hardly possible, each atomic region is usually approximated by a spherical region around the atom, where the radius is taken as its ionic, atomic, or covalent bond radius. The radial distribution of electron density around an atom is also useful to estimate the effective radius of an atom, particularly in ionic crystals. In an ionic crystal, the distance from the metal nucleus to the minimum in the radial distribution curve generally corresponds to the ionic radius. As an example, the radial distribution curves around K in o-KvCrO., (85) are shown in Fig. 19a. The radial distributions of valence electrons (2p electrons) exhibit a minimum at 1.60 A for K(l) and 1.52 A for K(2), respectively. These distances correspond to the ionic radii in crystals (1.52-1.65 A)... 

Lide, D.R. (2012) Ionic radii in crystals, in CRC Handbook of Chemistry and Physics (eds W.M. Haynes and D.R. Lide), CRC Press/Taylor and Francis, Boca Raton, FL. 

This new Internet edition has added 13 new subsections that can be accessed as interactive tables. These include tables on atomic and molecular polarizabilities, diffusion in gases and liquids, vapor pressure and density of mercury, ionic radii in crystals, surface tension, and other topics. All material in the printed Handbook is accessible in the Internet version as interactive tables and/or pdf displays. 

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