MEIS SURFACE-STRUCTURE DETERMINATION METHODOLOGY - APPLICATION TO NI(100)C(2X2)-0

100 keV H+ medium energy ion scattering (MEIS) blocking patterns have been measured using incidence in the < 210 > and < 310 > directions fr om the Ni (100)c(2 x 2)-O surface phase. These data formed the basis o f a structure determination through comparison with simulated data for different model structures. A detailed evaluation has been made of di fferent criteria for establishing the best-fit theoretical simulations , using R-factors based on chi-squared, from previous MEIS studies, an d from other surface crystallographic techniques (LEED and photoelectr on diffraction). A similar evaluation of criteria for establishing sig nificance and precision is presented. (C) 1998 Elsevier Science B.V.