New structures - new insights: Progress in structure analysis of nanoporous materials

In the recent past structure determination of microporous materials has experienced considerable developments in methodology. The FOCUS method: high resolution powder diffraction data used for direct method structure solution in combination with crystal chemistry based modelling. The models are retrieved from electron density maps calculated in direct method runs, energy minimized and checked through for realistic angles and distances values. The SUM-TF method: diffraction patterns at moderate resolution analysed with direct methods using a modified tangent formula which includes Patterson information for the structure solving. In this way the atomic resolution criterion for direct methods is bypassed. This overview gives a summary of the structures successfully solved using these new techniques. (C) 1998 Elsevier Science B.V. All rights reserved.