*> As I get older, I believe less and less in legends (AH)* *> ...the aristocracy of powder diffractionists is displaced (AleB)*
I don't believe in aristocracy either :-) After Bill David, Lambert van Eijck and I published Hugo Rietveld's glowing obituary <https://journals.iucr.org/j/issues/2016/04/00/es0421/>, I received a rough draft of the vL&S paper <http://journals.iucr.org/a/issues/2018/02/00/ib5058/>, and was frankly shocked. But after finding that others shared those views, I suggested a re-write of the paper to make it (perhaps) less controversial and more historical, supported where possible with evidence from the literature. Still, the paper seemed to address questions I myself had about the legend. 1) How could a young man, educated as a classical crystallographer (Bragg peaks, structure factors, Fourier transforms...) produce the revolutionary idea of simply refining the structure to fit the observed profile ? None of the professional crystallographers I knew accepted that idea - only physicists and chemists who used crystallography as a tool. It was a naive physicist's approach. 2) How could Rietveld (1967) in his first paper not emphasise this revolutionary departure from classical crystallographic techniques ? It was almost as if he didn't consider that refining magnetic moments and atom displacements was real crystallography, just a refinement problem where compromises had to be made to get a required result with an inadequate computer. 3) Why did Rietveld leave science in 1974 if he thought that he had achieved something remarkable ? He had a permanent job at a well funded laboratory and a technique that would eventually revolutionise powder diffraction. Ordinary people like me couldn't even get a job at Cambridge (thanks Mike :-) and had to live with a succession of 3 year contracts in foreign countries. When I first knew Hugo, he was a modest, unassuming man, unlike Loopstra who apparently pushed hard. When he saw that "*The response was slight, or, rather, non-existent*" perhaps like other crystallographers for 20 years he himself doubted the value of profile refinement. And no I don't think the crystallographic establishment should get to name it. Everyone knows what "profile refinement" means. On Sat, 18 Aug 2018 at 11:29, Le Bail Armel <le-bail.ar...@orange.fr> wrote: > Hi, > > > > >As I get older, I believe less and less in legends. In the IUCr 1999 > issue that I cited, I should have also mentioned that there is an > interesting article on p.4 called "*The Powder Diffraction Handicap > <http://ww1.iucr.org/news/v7n4/7-4.pdf>*" by Armel le Bail :-) > > > > Indeed, "never say never" is verified again. The powder diffraction > handicap (overlapping) can be considered as suppressed by XFEL > > https://www.xfel.eu/ where each single microcrystal of the powder > produces 3D diffraction data, and all data are recombined ! > > But for solving too simple problems, you will not have access to that > overloaded machine and will have to continue to use your laboratory powder > diffractometer and (now) classical approaches. > > > > So, once again, the aristocracy of powder diffractionists is displaced, > this time from third generation synchrotron to XFEL, amusing, new legends > will be built, probably. > > > > Best, > > > > Armel > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Please do NOT attach files to the whole list <alan.he...@neutronoptics.com > > > Send commands to <lists...@ill.fr> eg: HELP as the subject with no body > text > The Rietveld_L list archive is on > http://www.mail-archive.com/rietveld_l@ill.fr/ > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > -- ______________________________________________ * Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE * <alan.he...@neutronoptics.com> +33.476.98.41.68 http://www.NeutronOptics.com/hewat ______________________________________________
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com> Send commands to <lists...@ill.fr> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
