Surface States ond-Band Metals

Electron surface states on $d$-band metals are investigated by the method of matching the crystal wave function at the surface to the solution outside. On a (100) surface of an fcc metal such a state is found at an energy corresponding to 4-5 eV below the Fermi level $E_{\mathrm{F}}$ in Ni and 5-6 eV below $E_{\mathrm{F}}$ in Cu. This state explains peaks in the density of states seen in photoemission from Ni and Cu.