Multi-Purpose Pattern-Fitting System RIETAN-2000 and its Applications to Microporous Mterials.

Abstract

A heavy-duty system of high performance, RIETAN-2000, has recently beendeveloped for Rietveld refinement, Le Bail refinement, whole-patternfitting based on a maximum-entropy method (MEM), and individual profilefitting. An original feature called partial profile relaxation isapplicable to (nearly) isolated reflections with relatively largeresiduals, which leads to better fits in these reflections. Thestate-of-the-art technology of MEM-based whole-pattern fitting allowsus to represent positional disorder, chemical bonds, and anharmonicthermal motion more adequately than the conventional Rietveld method.Four examples of applying RIETAN-2000 to microporous materials areintroduced to demonstrate its high ability to analyze structuraldetails.