AN AUTOMATED TENSOR LEED ANALYSIS OF THE NI(111)-C(4X2)-2CO STRUCTURE

The Ni{111}-c(4X2)-2CO system has been studied using fully dynamic low -energy electron diffraction. CO is found to occupy both hcp and fcc t hreefold hollow sites. This is in contrast to earlier conclusions from vibrational spectroscopy where assignment was made to bridge sites. T his study also represents an improvement over earlier SEXAFS and photo electron diffraction studies in that the full surface geometry is obta ined revealing significant bucklings of the nickel first and second su rface layers and points to possible bends and tilts of the CO molecule s.