Obituary

A. T. H. Lenstra (1942 - 2002)

[Lenstra]

Albert (Ab) Lenstra died on August 18, 2002 aged 60. He was professor in structural chemistry at the U. of Antwerp (UIA). He obtained his doctorate in Utrecht, in the crystallography laboratory founded by J.M. Bijvoet. His research was in the field of X-ray structure analysis of small molecules, in particular the study of deformation densities for which he needed to give special attention to quality control of diffraction intensity measurements. Through this work he became an expert in the use of Bayesian statistics and, with his coworkers, had several publications on this domain, the last of which appeared in 2001.

Through his research, his students and his post-docs from Russia and China, Ab had many friends throughout the world.

He had been a member of the Belgian Nat’l Committee for Crystallography since 1994 and he represented Belgium at many international congresses. On the way to ECM-20 in Krakow, he fell victim to an illness that, a year later, was to prove fatal. He accepted this without the slightest complaint.

We shall not forget the notable human quality of Ab Lenstra. His modesty prevented him from pushing himself. As a scientist he always sought after truth, a quality found also in his humanity where he was direct in word and deed.

The members of the Belgian Nat’l Committee for Crystallography and many others in the IUCr will continue to honour his memory.

Karl Michel