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Powder Diffraction Structure Determination and Refinement from Powder Diffraction Data

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Powder Diffraction Structure Determination and Refinement from Powder Diffraction Data Berichte aus Arbeitskreisen der DGK Nr. 9 VII. Workshop Powder Diffraction Structure Determination and Refinement from Powder Diffraction Data Robert E. Dinnebier (ed.) Deutsche Gesellschaft für Kristallographie 2000 - ii - Acknowledgement The VII international workshop on powder diffraction, October 4. – 8, 2000 at the Laboratory of Crystallography of the University of Bayreuth (Germany) was organized by the Powder Diffraction Group of the German Society of Crystallogra- phy DGK. We are grateful to the Universität Bayreuth for supplying technical assistance, lecture halls and PC pools free of charge. We are further grateful for financial support from - Deutsche Gesellschaft für Kristallographie (DGK) - Deutsche Mineralogische Gesellschaft (DMG) - International Union of Crystallography (IUCr) - International Centre for Diffraxction Data (ICDD) - Clariant GmbH, Frankfurt - Stoe & Cie, Darmstadt - Bruker AXS, Karlsruhe - Cambridge Crystallographic Data Centre (CCDC), Cambridge - Molecular Simulation Inc. (MSI), Cambridge - Böhringer Ingelheim, Biberach a.d. Riss - Crystal Impact, Bonn - BASF AG, Ludwigshafen - Philips Analytical, Almelo Due to the generous support, it was possible to keep registration costs for this workshop low and to award 15 travel grants to students to cover all local costs at Bayreuth as well as part of their travel costs. - iii - - iv - Preface The complexity of crystal structures which can be solved and/or refined from powder diffraction data has been increasing steadily throughout the last few years. In particular further developments of “traditional” algorithms for structure determination in reciprocal space as well as the application of global optimiza- tion algorithms in direct space have reached a level which for the first time al- lows powder diffraction to be used as an alternative technique to single crystal diffraction for inorganic and small molecule structures. As a consequence, the powder diffraction method is gaining a lot of interest, particularly in the chemical and pharmaceutical industry. Despite this success, we can not yet speak of it being a routine method. Therefore, because this field of research is developing rapidly, so there is a need for suitable training. How is the workshop organized ? As for the previous 6 workshops of this series, there are lectures, tasks and practical exercises but the training concept is different. In view of the short time available, the participant will decide by him- self, which programs he wants to try out and which of the many offered exercises he wants to perform. All tutorials and most of the software can be found on the distributed workshop CD. The course is intended for beginners as well as advanced users of powder diffraction methods in materials, geological, physical, chemical and pharmaceu- tical sciences. The course will provide an overview of the state of the art methods for structure determination and refinement from powder data. Examples at differ- ent levels of complexity will be provided including: data reduction from powder diffraction patterns taken at ambient and non-ambient conditions, peak fitting and intensity extraction (LeBail- and Pawley methods), traditional structure determi- nation methods for powders (direct methods, Patterson search method), global optimization methods for structure determination in real space, combination of structure refinement and energy minimization, the Rietveld method (including the use of soft constraints and rigid bodies) and a comparison of Fourier analysis versus maximum entropy. Due to the large number of contributions, it was necessary to publish the Rietveld tutorial for this workshop in a separate issue of this series (Berichte aus Arbeitskreisen der DGK Nr. 8). All relevant information of this workshop is available online at http://www.uni-bayreuth.de/departments/crystal/workshop2000/. - v - - vi - CONTENTS Workshop Schedule.............................................................................................. 1 Freely Available Software to Assist in Solving Structures from Powder Dif- fraction................................................................................................................... 7 Lachlan M.D. Cranswick EXPO2000: a New Package for Ab-initio Structure Solution from Powder Data........................................................................................................ 49 Angela Altomare, Carmelo Giacovazzo , Antonietta Guagliardi, Anna Grazia Giuseppina Moliterni & Rosanna Rizzi The Solution of Molecular Structures by Patterson Search Methods Using Powder Diffraction Intensity Data.................................................................... 75 Jordi Rius Monte Carlo Methods ........................................................................................ 85 Maryjane Tremayne & Colin Seaton Crystal Structure Determination of Tetracycline Hydrochloride with Powder Solve .............................................................................................. 97 Marcus A. Neumann, Frank J. J. Leusen, G. Engel, C. Conesa-Moratilla & S. Wilke DASH Tutorial 1............................................................................................... 121 Kenneth Shankland & William I. F. David DASH Tutorial 2............................................................................................... 141 Harriott Nowell & Kenneth Shankland Combined Method for "Ab Initio" Structure Solution from Powder Diffrac- tion Data: The ENDEAVOUR, Software....................................................... 149 Holger Putz Structure Determination from Powder Data with TOPAS.......................... 169 Arnt Kern Energy Minimization Techniques................................................................... 181 Martin U. Schmidt Maximum Entropy Method Applied to Crystallographic Problems........... 191 Martin Schneider & Sander van Smaalen BRASS: The Bremen Rietveld Analysis and Structure Suite ...................... 201 Reinhard X. Fischer, Thomas Messner & Dethart Kassner High Pressure Powder Diffraction.................................................................. 209 Ross J. Angel - vii - Application of X-Ray Powder Diffraction in Pharmaceutical Sciences...... 229 Peter Sieger Structure Determination from X-Ray Powder Data of Notoriously Difficult Materials............................................................................................................239 Hermann Gies The Importance of the Inorganic Crystal Structure Database ICSD for the Application of Rietveld-Methods ....................................................................253 Rudolf Allmann - viii - Workshop Schedule Events Building Room Registration Desk Naturwissenschaften II Foyer Industrial Exhibition + Naturwissenschaften II Foyer Posters Lectures Naturwissenschaften II H19 Exercises BIX 24 GEO S24b Geisteswissenschaften II U.17.2 Coffee/Tea Breaks Naturwissenschaften II Foyer Lunch Mensa (Wednesday till Friday) Pizza (Saturday) Naturwissenschaften II Foyer Philips Mixer (Wednesday) Bayerisches Geoinstitut (BGI) 2nd floor Conference Dinner Speisegaststätte “Röhrensee” (Friday) Pottensteinerstrasse 5 Tel: 0921-64593 - 1 - Wednesday, October 4, 2000 Direct Space methods (Global optimization) When ? What ? Who ? 8.00-10.00 Registration 9.30 Opening and Welcome R. Dinnebier, S. van Smaalen 9.45 Simulated Annealing (DASH program) W.I.F.David 10.30 Global Optimization Algorithm K. Shankland 11.15 Coffee/Tea 11.45 Monte Carlo Methods M. Tremayne 12.30 Lunch Break (Mensa) 13.30 Full-profile Simulated Annealing Method for P. Bruce, Solving Complex Molecular Structures from Y. Andreev Powder Diffraction Data 14.15 Powder Solve in Action F. Leusen 14.45 Coffee/Tea 15.15-18.45 Exercises Part I All 19.00 Mixer (sponsored by Philips Analytical) - 2 - Thursday, October 5, 2000 Direct-, Patterson methods/ Energy minimization Time ? What ? Who ? 9.00 Advances into the EXPO Package C. Giacovazzo 10.00 Patterson Search Methods J. Rius 11.00 Coffee/Tea 11.30 Energy Minimization Techniques M .U. Schmidt 12.30 Lunch Break (Mensa) 13.30 Simultaneous Optimization of Pattern Differ- H. Putz ence and Potential Energy: Structure Solution Using Endeavor 14.00 DASH Demonstration S. Maginn 14.30 Coffee/Tea 15.00-18.45 Exercises Part II All - 3 - Friday, October 6, 2000 Rietveld refinement Time ? What ? Who ? 9.00 New Rietveld Program JANA S. van Smaalen 9.45 Presentation of a new Rietveld Program R. X. Fischer 10.30 Coffee/Tea 11.00 Case Study of a Complicated Rietveld Re- R. Dinnebier finement using GSAS (Preparation for Exercise) 12.30 Lunch (Mensa) 13.30 Rietveld Refinement at High Pressure R. Angel 14.30 Structure Determination from Powder and A. Kern Single Crystal Data by Simulated Annealing. 15.00 Coffee/Tea 15.30-19.00 Exercises part III All 19.30 Informal Get Together and Dinner - 4 - Saturday, October 7, 2000 Special strategies/ applications/ data bases Time ? What ? Who ? 9.00 The ICSD Database R. Allmann 9.30 The ICDD Database J. Faber 10.00 The CCDC Database J. Cole 10.30 Coffee/Tea 11.00 Freely Available Software Tools to Aid in L. Cranswick Structure Solution from Powder Diffraction 11.45 Structure Determination of Complicated Frame- H. Gies work Structures from Powder Data 12.30 The Maximum Entropy Method M. Schneider 13.00 Pizza 14.00 Application of Powder Diffraction in Pharma- P. Sieger ceutical Sciences 14.30 Coffee/Tea 15.00-19.00 Exercises / Demonstrations part IV All Sunday, October 8, 2000 Exercises Time ? What ? Who ? 9.00-12.00 Exercises Part
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