Crystal engineering: from molecules and crystals to materials
The first Advanced Study Institute offering a coherent approach to crystal engineering as an integrated interdisciplinary area of research was directed by D. Braga (U, di Bologna, Italy) and A.G. Orpen (U. of Bristol, UK). A major challenge of the School was having teachers of organic, inorganic, organometallic, theoretical, materials chemistry and biochemistry stimulate productive interactions among experts in modeling, theoretical calculations, crystal synthesis, product design and structural characterization and manipulation of physical properties. The 500 page proceedings will provide a state-of-the-art description of the field and offer new ideas to young scientists interested in multidisciplinary fields. The lectures provoked considerable discussion, with particular interest expressed in the properties of molecular materials and non-covalent bonding. Short talks were presented by students and senior attendees and the majority of attendees presented posters. Computer tutorials on the Cambridge Structural Database, run by CCDC staff were presented at two levels of complexity depending on previous experience. Round-table discussions on (i) growing crystals and (ii) crystal engineering in industry provoked extensive debate and participation by both teachers and students.
L. Scaccianoce (Cambridge) and C. Zybill (Jena) were awarded the 1999 Erice Vaciago Prize for the most dynamical “students” in the lecture hall. The School was attended by 124 participants from 29 Nations.
Dario Braga, Course Director
Erice School of Data Mining
Crystallography was among the first disciplines to recognize the importance of computer storage of data. Databases established in the early 70’s provide an opportunity to mine the wealth of knowledge they contain. The purpose of this Erice School was to provide an overview of the methodologies currently used for data mining in crystallography and outline the advances needed for a more effective and efficient exploitation of databases.
The first part of the School, devoted to methodologies and tools, provided a survey of data acquisition and validation and knowledge representation techniques and an introduction to the many paradigms of machine learning. This was followed by a journey through the various stages of data mining, from prospecting to sampling, knowledge extraction and refinement. A plethora of choices exist to extract knowledge from the databases, from visual and statistical techniques to artificial intelligence. No single approach will perform well on every problem and combining results obtained using different approaches can increase the usefulness of the data mining exercise.
The second part of the School focused on applications of data mining to structure classification and prediction, structure-activity relationships, materials design and biotechnology. Superb examples of these applications were presented in supramolecular chemistry, genomics, inter-molecular interactions and drug design.
Because data mining starts with deposits, it is necessary to provide incentives to the scientific community to deposit their data. Good results can only be obtained from good data, though, pointing to the importance of validating the data. While several methodologies have already proven useful for mining crystallographic databases, significant progress will require adopting a common language, common standards and establishing test datasets so as to put in place a more rigorous process for assessing the performance of the various tools. As databases continue to grow and initiatives such as genomics and proteomics progress, mining the databases becomes both a necessity and an opportunity.
In bringing together crystallographers and computer scientists in the beautiful surroundings of Erice, the School was described as a “first” or “blind date”. The clear wish, expressed by the majority of the participants, for further interactions speaks well of the commitment of the two communities to join forces in extracting the rich scientific knowledge embedded in crystallographic databases.
Suzanne Fortier, Course co-director
La Notte d’Argento
The International School of Crystallography at Erice marked its 25th anniversary in grand style with a series of events called “La Notte d’Argento”. A mixture of fantasy, humour and fun, devised by S. Fortier (Course Director, 1997 and 1999) and P. Spadon (Secretary of the School).
The 200 participants of the Crystal Engineering and Data Mining courses assembled in the S. Rocco Court displaying “argento” ornaments (long dresses, bow ties, scarves and silver beards). Accompanied by a local brass marching band, they walked through the millenarian streets of Erice, cheered by the local residents who recorded the procession on film. They were greeted in the S. Francesco court with sparkling wine and Italian folksongs. Attempts to toast and roast Lodovico by S. Fortier, J. Howard, P. Beurskens, L. Nassimbeni and H. Schenk (participants in the 1974 inaugural crystallographic course) were cut short; due to “religious” attention to punctuality in Erice, guests must not be late for dinner and face cold pasta. All participants were seated at tables for dinner,something that had not happened within the S. Francesco since the Pope’s visit. A Sicilian folk group engaged the crowd in song and dance that led to dancing through the night in the court of S. Francesco. Suzanne and Paola, all of Paola’s tireless helpers, and the Goddesses of Erice (for providing mild temperature and plenty of silver stars), are to be thanked for this unforgettable night.
Lodovico Riva di Sanseverino