SURFACE-STATES AT THE M-POINT ON CU(100)

We have calculated the electronic structure of Cu in the vicinity of t he (100) surface. We used the relativistic SCF-LMTO-ASA method, within a slab geometry and including the surface dipole terms. We find two s urface states at the <(M)over bar -point>; the first lies about 0.2 eV above the d-band continuum and the second lies within a spin-orbit ga p near the top of the d-band continuum. Both states have been observed experimentally and our calculated dispersion relations are in reasona bly good agreement with the measurements. We have also carried out fir st-principles photocurrent calculations using the layer-by-layer poten tial functions and the spectra are in excellent agreement with previou s photoemission measurements. Copyright (C) 1996 Elsevier Science Ltd.