2593.     ---------------.  [PAULING, L.]  Nature of the Interatomic Forces in Metals.  II.  Atomic Radii and Interatomic Distances in Metals.  Jour. Am. Chem. Soc., vol. 69, 1947, pp. 542-553; Chem. Abs., vol. 41, 1947, p. 5772.

        Concept that the metallic bond is equivalent to resonating covalent bonds permits the formation of a system of atomic radii that can be used to calculate interatomic distances in metals and intermetallic compounds and to interpret observed interatomic distances in terms of the electronic structures of the crystals.  An equation is developed to express the change in covalent radius (metallic radius) of an atom with change in bond number, or in coordination number, if the valence remains constant; the stabilizing, bond-shortening effect of the resonance of shared-electron-pair bonds among alternative positions also is taken into consideration.  This equation is applied to the empirical interatomic-distance data for the elementary metals to obtain a nearly complete set of single-bond radii.  Cr, Mn, and Sn exist in metals in 2 forms:  A small, high-valent form and a larger, low-valent form.  Both kinds of Mn atoms coexist in a- and β-Mn.  In many metals, each atom is attached to some of its neighbors by strong bonds and to others by much weaker bonds.  An extreme case is β-W, in which there are straight strings of strongly bonded atoms; similar strings also are present in the a-U structure.  The use of the radii is illustrated by application to the structure of cementite and AuSn.