A comparison of reliability (R) factors in a LEED structural analysis of the copper (111) surface

Abstract

A large experimental data set of I(V) curves was collected over an energy range 50-400 eV at three diffraction geometries from the copper (111) surface. The experimental curves were compared with I(V) curves calculated from model structures. The result obtained for the relaxation of the topmost layer is -0.3%+or-1% (+or-0.02 AA) of the bulk interlayer spacing. The precision of the result comes from the large experimental data base and the application of statistics to an R-factor analysis. R-factors are presented for the formalisms both of Zanazzi and Jona and of Pendry. The two R-factor analyses give similar results for the relaxation of the copper (111) surface. However, the Pendry R-factor is found to be more sensitive to model parameters and faster to compute than the Zanazzi and Jona R-factor.