Indaba III, Symmetry and Structure

About 60 delegates flocked to Skukuza, South Africa in the Kruger National Park, to attend the third Indaba of the South African Crystallographic Society, sponsored by the IUCr. The theme of the August 2000 workshop, 'Symmetry and Structure', was well suited to the 'Indaba' spirit, the study of a subject in depth from many different angles.

Henk Schenk, president of the IUCr, opened the proceedings with a review of the structure and activities of the Union, after which J. Boeyens (Pretoria) gave an overview of the interplay between symmetry, the time-space universe, and the fundamental laws of nature. D. Avnir (Jerusalem) discussed qualitative and quantitative measurement of symmetry, and speculated about the relation between symmetry, information content, and entropy. C. Graham (Pietermaritzburg) discussed chirality and time reversal symmetry in molecular and crystal optics, and a flamboyant H. Flack (Geneva) discussed the problems and pitfalls of the determination of absolute structure and absolute configuration.

The social highlight of the day was a game drive through the chilly winter night in the bushveld surrounding the camp. The spirits of the shivering participants flared up when they were treated to the rarely witnessed spectacle of a large herd of buffalo being attacked by a pride of lions.

 The next morning A. Janner (Nijmegen) compared the symmetry of snowflakes with that of DNA molecules. O.Vassilyeva (Kiev) reported on the structure and properties of copper complexes. P. Comba (Heidelberg) entertained everyone with a pair of chiral apples, the similarity between the 'Ascending and Descending' painting by Escher and German politics, and the amount of 'leftness' and 'rightness' in the faces of his twin daughters. M. Lofener presented a paper by A. Amann (Innsbruck) who was unable to attend, on the substance problem in chemistry and the use of large deviations theory.

E. Osawa (Toyohashi) kicked off the afternoon session with a new model to describe hydrogen bonds based on data extracted from the Cambridge Structural Database. After showing some interesting McGillavry memorabilia, H. Schenk (Amsterdam) discussed the influence of symmetry on direct methods.

Wednesday brought the first reports of participants having spotted the 'big five': elephant, lion, buffalo, rhino and leopard before breakfast. Undisturbed by the exuberance of the visual hunters, G. Desiraju (Hyderabad) discussed relationships between molecular and supramolecular symmetry. After tea, L. Nassimbeni (Cape Town) eloquently spoke about physico-chemical aspects of inclusion compounds. N. Harada (Sendai) demonstrated (on paper!) the mechanism of a light-powered molecular motor, and D. Levendis (Johannesburg) discussed the relation between pseudo-symmetry, superlattices, and disorder.

J. Flippen-Anderson (Washington) opened the last day with comments on rapid data collection and increased computing power, and a discussion of 'twins, disorder and other demons'. A cheerful A. Roodt (Bloemfontein) then discussed examples of chirality in coordination chemistry, and the new Cambridge Structural Database software was described by M. Fernandes (Johannesburg).

In the final session, K. Tornroos (Bergen) spoke about order-disorder phase transitions, W. Depmeier (Kiel) covered structural disorders in microporous materials, and J. Cai (Guangzhou) discussed racemic and enantiomeric complexes.

After a final game-spotting excursion, all attendants enjoyed tribal Zulu dancing, traditional 'potjiekos' for dinner, and a nonsense speech by the nestor of South African crystallography, Jan Boeyens, and a very witty Peter Comba. During the evening, Manuel Fernandes (Johannesburg) and Armin Wagner (Johannesburg/Berlin) shared a prize for presenting the best poster. Indaba III achieved its goal of being a highly stimulating and successful 'meeting of minds'.

Jan Dillen, U. of Stellenbosch

Participants of Indaba III in August 2000.