Computer simulation approach to reliability and accuracy in EXAFS structural determinations

The frequency distribution of different parameters of an EXAFS (extended X-ray absorption fine structure) spectrum can be directly sampled by analysing a population of simulated spectra produced by adding computer-generated noise to a reference pattern. The procedure gives statistical estimators of the parameters obtained with different data processing strategies in order to test the performance of a strategy, to evaluate the bias introduced by random noise, and to clarify the amount of information actually contained in an experimental spectrum. Results are given for the two simple local structures formed by an Ag atom surrounded by two O atoms or by six I atoms, respectively.