By using ab initio calculations, shear-induced energy changes in the electronic charge densities of face-centered cubic metals (Al, Ag, Ir) with various deformation properties were studied. The charge redistribution, described by the change in character of specific charge density critical points, was deduced from the values of the charge density, ρ, and its 3 principal curvatures, ρii, ρhh and ρvv. The change in character of the critical points was related to the energetics. For all 3 metals, ρhh vanished near to the unstable stacking configuration. The symmetry or asymmetry of the charge redistribution, measured by ρhh/ρvv, was suggested to an important factor determining stacking fault energies.

Topology of Electronic Charge Density and Energetics of Planar Faults in FCC Metals. N.Kioussis, M.Herbranson, E.Collins, M.E.Eberhart: Physical Review Letters, 2002, 88[12], 125501 (4pp)