Hi,
Reading again the Acta Cryst. (2018). A74, 88–92 paper : "So, summarized here, HS wrote in Dutch: ‘Loopstra had the idea that it should be better to use the whole powder profile rather than estimated intensities to solve structures, van Laar worked it out mathematically and Rietveld programmed it. Nowadays it is known as the Rietveld method’. HS submitted the raw manuscript without figures and photographs. At the time he was President of the IUCr, very busy and travelling a lot. So when he saw the article again, it was already printed, there were four illustrations provided by Rietveld himself, and slight changes had been made to the text, which in essence had changed its meaning. In the sentence above Loopstra was replaced by Rietveld and it now started with ‘Rietveld had the idea that...’. Also a last sentence about Rietveld’s hobby, as a jazz pianist, had been added." This is the "coup de grace"... But could Hugo Rietveld admit to be transformed in a simple programmer by ‘Loopstra had the idea that it should be better to use the whole powder profile rather than estimated intensities to solve structures, van Laar worked it out mathematically and Rietveld programmed it' ? Seriously, HS really think that Hugo Rietveld had absolutely no idea, and then worked out mathematically nothing ? This was a complete provocation to give to Hugo Rietveld access to such an insulting text against him before its publication. I just prefer to believe that Hugo Rietveld restored the truth by inserting ‘Rietveld had the idea that...’. instead of Loopstra. There is no proof of the contrary given by Loopstra himself, defined as a man "who apparently pushed hard" by Alan. He had a lot of time to push hard in order to contradict the legend and has done nothing apart using the method and citing quietly the 1969 paper from Hugo Rietveld. Best, Armel > Message du 18/08/18 12:24 > De : "Alan Hewat" > A : [email protected] > Copie à : "[email protected]" > Objet : Re: Rietveld > > > 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, I received a rough draft of the vL&S paper, 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 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" 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 > Send commands to eg: HELP as the subject with no body text > The Rietveld_L list archive is on > http://www.mail-archive.com/[email protected]/ > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > -- > ______________________________________________ > Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE +33.476.98.41.68 > http://www.NeutronOptics.com/hewat > ______________________________________________ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list Send commands to eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/[email protected]/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <[email protected]> Send commands to <[email protected]> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/[email protected]/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
