MEIS surface structure determination methodology: Application to Ni (100)c(2 × 2)-O

100 keV H+ medium energy ion scattering (MEIS) blocking patterns have been measured using incidence in the 〈210〉 and 〈310〉 directions from the Ni (100)c(2 × 2)-O surface phase. These data formed the basis of a structure determination through comparison with simulated data for different model structures. A detailed evaluation has been made of different criteria for establishing the best-fit theoretical simulations, using R-factors base on chi-squared, from previous MEIS studies, and from other surface crystallographic techniques (LEED and photoelectron diffraction). A similar evaluation of criteria for establishing significance and precision is presented.