Abstract
The electronic density of states at a planar and at a stepped FCC transition metal surface is calculated within the cluster-Bethe lattice approximation. The authors use a Husumi cactus formed by tetrahedra as a boundary condition instead of the Bethe lattice in order to take into account the effects of the close packing of the FCC lattice. The calculation is performed for a simple s-d Hamiltonian. Effects of the different topologies on the density of states appear very clearly in the calculation.