Am. Pendas et al., IONS IN CRYSTALS - THE TOPOLOGY OF THE ELECTRON-DENSITY IN IONIC MATERIALS - III - GEOMETRY AND IONIC-RADII, JOURNAL OF PHYSICAL CHEMISTRY B, 102(36), 1998, pp. 6937-6948
We present the application of Bader's topological analysis of the elec
tron density to geometric properties in ionic materials. Particular at
tention is paid to the concept of ionic radius, in relation to the sha
pes of ions in crystals, and to the various correlations among atomic
properties, i.e., electronegativities, deformabilities, etc., that it
induces. Using a simple model to fit our results to a theoretical fram
e, we show that ionic bonds display properties in complete parallelism
to those known in covalent bonds. This allows us to define unambiguos
ly the strength of an ionic bond, which is found to correspond to Paul
ing's bond valence.