Meeting report

Zürich School of Crystallography
Bring Your Own Crystals

Zürich, Switzerland, June 2013

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The fifth Zürich School of Crystallography took place at the Inst. of Org. Chem. at U. Zürich (UZH), June 9-22, 2013. The 19 participants were instructed in the theory and practice of small-molecule single-crystal X-ray crystallography. Despite the intensity of the program, the enthusiasm of the participants remained high throughout. They appreciated the personal attention made possible by the 2:1 student:tutor ratio. The participants included 13 PhD and 1 MSc student, and a postdoc. The 8 women and 11 men, with ages ranging from 24 to 50, came from Canada, Finland, Ghana, Italy, India, Nigeria, Poland, Romania, Slovenia, Switzerland, Sweden, Thailand, Turkey, The Ukraine and Uzbekistan. The 10 tutors were from the Universities of Basel, Bern, Geneva, Zürich, the EPFL Lausanne, the ETH Zürich and the Inst. of Physics, Prague.

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Alternating lectures and practical work allowed the participants to assimilate the theory and practical aspects together. The practical work included hands-on experience in groups of two at one of the five diffractometers available in the chemistry institutes at the UZH and ETH Zürich. The tutorial exercises and structure refinements were done in the computer classroom of the Inst. of Organic Chemistry. We gave the participants two test data sets to learn to use the software and recognise and resolve unexpected difficulties with structures. Each participant then solved the structure of the compound they had provided crystals of in the lead-up to the School. They were excited to solve the structure of a compound of interest to them. The samples provided a wide range of crystal types (organic, organometallic, coordination polymer, natural product and mineral) and some included challenges, such as twinning, disorder, solvent inclusion, and unusual or ambiguous space groups. All participants were able to complete their structures successfully.

Each participant gave a ten minute presentation on their structure. Those desiring credit points took a two-hour written exam. Others took the exam to test their knowledge. Each day concluded with a discussion of the experiences. We offered repetition lectures on topics nominated by participants who felt that they did not quite grasp a certain aspect the first time. Discussions with the tutors often continued over the evening meal. Social events included a mixer, barbeque and a half-day excursion to the Swiss Light Source and SINQ neutron spallation facility of the Paul Scherrer Institute.

The central goal of the School is to equip each participant to determine structures when they returned to their home laboratory. The practical sessions were designed to allow the participants to go behind button-pushing and understand the operations they performed and how to evaluate the accuracy and relevance of their results.

Every participant completed a questionnaire. They often suggested including more example structures, but we believe a balance of theory and practical work is important. Each participant received a certificate and a copy of 'Crystal Structure Refinement, A Crystallographer's Guide to SHELXL' by Peter Müller, donated by the IUCr and OUP. After two weeks together, many new friendships had been established.The personal impressions of one of the participants are given further below. The next School will be held in June, 2015.

We are very grateful for the generosity of the sponsors: Institute of Org. Chem. UZH, Swiss Society of Crystallography, Cambridge Crystallographic Data Centre, European Crystallographic Association, IUCr, Verlag Helvetica Chimica Acta, Oxford U. Press, Agilent Technologies, Bruker AXS, Oxford Cryosystems and the X-ray Diffraction Services, CSEM, U. of Neuchâtel, and the Chemistry Platform of the Swiss Academy of Sciences.

Tony Linden and Hans-Beat Bürgi

Excerpts from the report of a participant

The school featured excellent lecturers/tutors assembled by Tony Linden (Editor: Acta Cryst. C; U. Zürich) and Hans-Beat Bürgi (Emeritus U. Bern/U. Zürich), which included H. Flack (Emeritus U. Geneva), J. Hauser, P. Macchi (both of U. Bern), G. Chapuis (Emeritus EPFL: Lausanne), O. Blacque (U. Zürich), M. Neuberger (U. Basel), L. Palatinus (Inst. Physics, Prague) and M. Wörle (ETH: Zürich). I’ve been involved with X-ray diffraction before, but had never solved a structure of my own, nor did I understand the meaning of much of the data commonly reported with X-ray diffraction data. We were able to see and tour Switzerland's Synchrotron facility and meet scientists there who are involved in X-ray, neutron and related diffraction experiments. It was wonderful to get to know students from very wide backgrounds and almost every corner of the world. The ZSC provided me with all the tools I need to solve crystal structures but also taught me what the common mistakes are and how to recognize them. I would highly recommend this course for anyone wanting to expand their knowledge of the subject or as a refresher course for those who might want more cutting-edge instruction in modern crystallography.