Surface structures from low energy electron diffraction. (Overlayer systems)

Recent advances in LEED theory have made it possible to use intensity/energy spectra to investigate the contents of the surface unit cell. Previously diffraction patterns could yield only the size and shape of the surface cell. The authors report the first structure to be deduced in this manner: that of c(2*2) sodium on nickel. Amongst other things, it is deduced that the spacing between the sodium and topmost nickel layer is 2.9+or-0.1 AA.