Charge transfer on the metallic atom pair bond, and the crystal structures adopted by intermetallic compounds

TL;DR

This paper supports Pauling's charge transfer theory in metallic alloys by showing electronegativity differences lead to ideal packing ratios and that lattice parameters of intermetallic compounds can be accurately predicted from atom-pair bond lengths.

Contribution

It provides empirical evidence linking charge transfer to atomic radii ratios and demonstrates accurate prediction of lattice parameters from bond lengths in intermetallics.

Findings

Electronegativity and valence differences support charge transfer in alloys.

Lattice parameters can be predicted from atom-pair bond lengths.

Atomic radii ratios are adjusted by charge transfer to match ideal packing.

Abstract

Pauling had proposed that charge is transferred from the more electronegative atom to the less electronegative one during metallic alloying. An expression has recently been derived for the energy of the unlike atom-pair bond using that concept. In this paper, Pauling's view is further supported by showing that the electronegativity and valence differences between unlike atoms in binary metallic alloys are of the required magnitude and direction so as to bring the metallic radii ratio R_A/R_B by charge transfer to a value r_A/r_B for ideal packing in an intermetallic compound. It is also demonstrated that lattice parameters of intermetallic compounds belonging to several crystal structure types can be obtained with excellent accuracy from the length of the atom-pair bond.