On thed-electron surface density of states of transition metals

It is shown that thed-electron surface density of states of a transition metal is strongly influenced not only by “off-diagonal” surface effects (e.g. reduction of nearest neighbors at the surface) but also by “diagonal” surface effects. Latter result from differences in the effective atomic potential for differentd-orbitals. They lead generally to large resonant contributions to the surface density of states. It is demonstrated that the “diagonal” effects must be included in any realistic calculation of the surface density of states.