Analysis of weighting schemes

Eighteen weighting schemes were implemented, together with two procedures of weighting modification to lessen the effects of outliers. Thirteen known structures were refined using the available weighting functions, obtaining for each structure many different minima. The solutions having the lowest R index do not give the best distributions of 〈wΔ²〉 against |F| and resolution. Possibly the accepted model could be one which gives the `best' estimates of the standard uncertainties rather than the lowest R.