Meeting report
[Congress Report]

Bragg Lecture

The 1999 Bragg lecture entitled 'Polymorphism; The Same yet Different' given at the Glasgow IUCr Congress by Jack Dunitz, ETH, Zurich reflected the change in outlook of chemists towards polymorphs during his lifetime, from an unwanted nuisance to a thriving research field. Prof. Dunitz suggested that the impetus for this change of attitude came from the challenge of crystal engineering in the pharmaceuticals industry, and the need to predict crystal structures and molecular properties.

He related the 'Strange Case of the Disappearing Polymorphs'. This ability for one thermodynamically stable form to dominate over another polymorph can have important implications for the pharmaceutical industry, especially when litigation and a lot of money is involved.

Based upon examination and analysis of many polymorphs, Dunitz has concluded that 'The optimal packing of a collection of identical molecules necessarily leads to the densest packing'.

Pam Thomas, BCA Newsletter, Sept. 1999