Dear Henk, I am not sure if this is what was intended in your commentary and e-mail, but I read from it the point that have heard often over the years, which is that someone is less than fully deserving of scientific credit because “s/he only developed the software” and in particular the term "the Rietveld Method” neglects the range of contributions from others in the scientific process. I think this needs a response.
There is no doubt that pattern fitting for extracting peak intensities predates the 1967 and 1969 papers from Hugo Rietveld, even though back then peak areas were most commonly estimated with a planimeter (https://en.wikipedia.org/wiki/Planimeter — I can remember my father around then using one for chromatography) or cutting and weighing. Likewise many people worked on developing the parameterization that allowed quantitative modeling of CW neutron diffraction peaks (though notably my understanding is that the well-known Cagliotti equation is a reformulation that Hugo first published, but credited to Cagliotti.) Van Laar sometime later contributed greatly to our understanding of low-angle asymmetric peak broadening (but again, fairly or not, most credit goes to Finger, Cox and Jephcoat who first released a general purpose program, even though Eddy and David first showed that it could be coded). I would guess that many people discussed the idea of determining crystallographic parameters by directly fitting to a diffractogram, but Hugo first developed an Algol code that actually implemented that concept, in a time when tackling such a large problem with the tiny computers available those days was an incredible achievement. If that was not enough, since Algol was not widely used, he then rewrote his code in Fortran to make his method more available. His Fortran code offered quite sophisticated crystallographic models, including magnetic scattering, and allowed complex groupings of parameters. Taking the idea of full pattern fitting from a concept to a method required considerable innovation. As one example, Hugo invented an intensity extraction algorithm that, as far as I am aware, is in every current program powder fitting in current use. Hugo’s extraction method was later incorporated into the LeBail method, when Armel came up with his smart idea to recycle those intensities. One measure of how far ahead of the curve Hugo’s work had been is to look at how long it took to see widespread acceptance. Around 1985, when I was first exposed to it, it was only just becoming be used outside of a few choice labs. Incidentally, what I used then was a code that had been passed through several hands and modified in each, but was based on Hugo’s original Fortran implementation. My understanding is that just about every Rietveld code that was available through to the 1990’s, with the one exception of GSAS, contained some of Hugo’s code. Hugo was one of many, many people who contributed to modern powder diffraction practice, but his solo work handed the world a tool which invented my field — powder diffraction crystallography — and I am most respectful of that. I cannot speak for others, but I personally will continue to use the term Rietveld analysis to honor an accomplishment that was well ahead of its time. It did not occur in a vacuum — little in science does, including the work of both Newton and Einstein — but still was an incredible step forward. Brian On Aug 9, 2018, at 5:32 AM, h.sch...@uva.nl<mailto:h.sch...@uva.nl> wrote: Bob van Laar and I wrote an article about the development of the powder Profile Refinement at the Reactor Centre Netherlands. This method is later called Rietveld refinement. We show that there were three persons involved in this enterprise, Bert Loopstra for the idea, Bob van Laar for the mathematical treatment and Hugo Rietveld for the computer program, rather than one. For all users of the method it will be interesting to read. The article (Acta Cryst. (2018). A74, 88-92) is Open Access and can be downloaded from: http://journals.iucr.org/a/issues/2018/02/00/ib5058/ib5058.pdf At the moment it is the most read article of Acta Cryst. A of the last 6 months: http://178.33.252.149/a/services/mostread.html Kind greetings, Henk Schenk ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com<mailto:alan.he...@neutronoptics.com>> Send commands to <lists...@ill.fr<mailto: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/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 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/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
