POWDER X-RAY CRYSTAL STRUCTURE ANALYSIS OF BASO_4 BY MAXIMUM LIKELIHOOD ESTIMATION

摘要

It has been reported1 that the crystal structure of BaSO_4 optimized by the application of maximum likelihood estimation (MLE) to powder diffraction data attached to a Rietveld program RIETANFP~1 goes closer to that obtained by a single-crystal method rather than the results of the Rietveld refinement applied to the same data, which is likely to be caused by the effect of particle statistics. In this study, we have investigated the effects of crystallite size and rotation of specimens upon the results of powder structure analysis of BaSO_4 by the Rietveld and MLE methods.