On the asphericity of d electron clouds near transition metal surfaces

Publisher Website
Google Scholar
Abstract
The charge density of d electrons around a bulk atom or low‐index facets atoms of fcc Ni, bcc Fe, and hcp Co are studied within the tight‐binding scheme using a moment method. The occupation numbers of each orbital are obtained. It is shown that the asphericity of the charge density is increased when going from a bulk to a surface site because the differences between orbital occupation numbers is less than 0.20 ? for a bulk atom but can reach ?0.44 ? for a surface one. The consequences upon preferred adsorption sites are discussed according to the electronic affinity and size of the adatoms.