A quasi-dynamic low-energy electron diffraction analysis was performed for the Ir(100)-(1 x 5) surface in the energy range from 50 to 440eV. On the whole 9 geometries of the reconstructed 1 x 5 surface unit cell were calculated with 12 first to second layer relaxations for each. Comparison with experimental I(E) curves through the Pendry r-factor prefers clearly the hexagonal bridge model with a buckling of 0.5Å and first to second layer distance of 1.98Å in agreement with full dynamical treatments. The variation of the r-factor with different surface geometries was also similar to the full dynamical calculation and parallels the more exact curve only with an upward shift. So the quasi-dynamic method proves to be successful even for very complex surface structures saving much computer efforts.

Quasidynamical LEED Structure Determination of the Ir(100)1 x 5 Surface Reconstruction. N.Bickel, K.Heinz: Surface Science, 1985, 163[2-3], 435-43