Re: Rietveld ESD calc fortran code typo?

Thanks a lot for that Jonathon. The code is helping me understand the algorithm, in particular the implementation of the double sum. Currently in the process of reproducing it in python to get around my essentially complete lack of knowledge in fortran so I can properly understand it. On Thu, 16

Re: Rietveld ESD calc fortran code typo?

Dear Matthew That fortran snippet was corrected in Appendix 1 of Andreev's paper here: https://doi.org/10.1107/S002188989300891X It is a shame that implicit none was not part of fortran 77. The google search resul leading me to that was: https://www.researchgate.net/publication/359342753_Pro

Re: Rietveld condamnation considered as established by some more people

factors. Then comes the Rietveld refinement anyway.envoyé : 18 août 2023 à 17:00de : Alan W Hewat à : Le Bail Armel cc : "rietveld_l@ill.fr" objet : Re: Rietveld condamnation considered as established by some more peopleI have no problem with Rietveld's prize Armel. Crystallograph

Re: Rietveld condamnation considered as established by some more people

e :* Alan W Hewat > *à :* Le Bail Armel > *cc :* rietveld_l@ill.fr > *objet :* Re: Rietveld condamnation considered as established by some > more people > > Bonjour Armel. > > No, it was van Laar who initiated it. He was annoyed that I had praised > Rietveld too much in my

Re: Rietveld condamnation considered as established by some more people

août 2023 à 11:30de : Alan W Hewat à : Le Bail Armel cc : rietveld_l@ill.frobjet : Re: Rietveld condamnation considered as established by some more peopleBonjour Armel.No, it was van Laar who initiated it. He was annoyed that I had praised Rietveld too much in my own accounts. http://hewat.net/science

Re: Rietveld condamnation considered as established by some more people

il method" and based on the Rietveld (Loopstra ??? proove it please) decomposition formula ? envoyé : 16 août 2023 à 19:08 de : Alan W Hewat mailto:alan.he...@neutronoptics.com>> à : Le Bail Armel mailto:le-bail.ar...@orange.fr>> cc : "rietveld_l@ill.fr<mailto:rietveld_l

Re: Rietveld condamnation considered as established by some more people

me. > > Best > > Armel > > PS - Why to insert a reference to the 1981 Pawley paper in a 1988 paper > where his > > method was not used but another method much later named "Le Bail method" > and > > based on the Rietveld (Loopstra ??? proove it please) decom

Re: Rietveld condamnation considered as established by some more people

on formula ?envoyé : 16 août 2023 à 19:08de : Alan W Hewat à : Le Bail Armel cc : "rietveld_l@ill.fr" objet : Re: Rietveld condamnation considered as established by some more peopleBonjour Armel. In answer to your question "Where did they find the text of the judgement ?" please

Re: Rietveld condamnation considered as established by some more people

My personal feelings are that regardless of the origin of the idea, Hugo did the work that made crystallographic full pattern fitting possible. That implementation was not just a “programming task” as the minimal capabilities of computers of the day required significant innovation for memory and

RE: Rietveld condamnation considered as established by some more people

outube.com/watch?v=WsPBB6azzX4 From: rietveld_l-requ...@ill.fr On Behalf Of Alan W Hewat Sent: Thursday, August 17, 2023 5:40 PM To: Le Bail Armel Cc: rietveld_l@ill.fr Subject: Re: Rietveld condamnation considered as established by some more people Armel, it's not about you :-) But in yo

Re: Rietveld condamnation considered as established by some more people

Dear Luca. Since I administer the Rietveld mailing list, I could have changed the name years ago when Van Laar and Schenk published their history, with which I largely sympathise. I didn't, because everyone now calls it "Rietveld Refinement", a name invented by Terry Sabine, who worked with Rietve

Re: Rietveld condamnation considered as established by some more people

Given the involvement of Alan in the early days I would be confident to trust his view. So why we don't try to fix a bit the mistake. We could: - start renaming this list as Loopstra-Rietveld list ;-) ( I would keep the name Rietveld in hit, first who got the idea, second the programmer) - start

Re: Rietveld condamnation considered as established by some more people

Armel, it's not about you :-) But in your 1988 paper you did not reference Pawley (1980) and even Rietveld only appeared as #14 https://www.researchgate.net/publication/228084768_Ab_Initio_Structure_Determination_of_LiSbWO6_by_X_ray_Powder_Diffraction#fullTextFileContent But let's not change the s

Re: Rietveld condamnation considered as established by some more people

It's a widespread phenomenon. What about America being named for Vespucii rather than Columbus? On Thu, 17 Aug 2023, 11:49 Le Bail Armel, wrote: > >And there are other examples. See this brief review of "Whole Pattern > Fitting - The Pawley Method" (1980) yet few people now attribute this kind

Re: Rietveld condamnation considered as established by some more people

>And there are other examples. See this brief review of "Whole Pattern Fitting - The Pawley Method" (1980) yet few people now attribute this kind of profile refinement to Pawley. http://pd.chem.ucl.ac.uk/pdnn/solve1/pawley.htmFew people ? At least me :https://onlinelibrary.wiley.com/iucr/itc/Ha/c

Re: Rietveld condamnation considered as established by some more people

And there are other examples. See this brief review of "Whole Pattern Fitting - The Pawley Method" (1980) yet few people now attribute this kind of profile refinement to Pawley. http://pd.chem.ucl.ac.uk/pdnn/solve1/pawley.htm On Wed, 16 Aug 2023 at 19:33, wrote: > Le Bail Armel schreef op 2023-0

Re: Rietveld condamnation considered as established by some more people

Le Bail Armel schreef op 2023-08-16 18:45: In a book : HOW SCIENCE RUNS – IMPRESSIONS FROM A SCIENTIFIC CAREER. BY ERIC J. MITTEMEIJER Reviewed by Mike Glazer "In another section, the author has some criticism about the famous Rietveld method in powder diffraction. He points out that the

Re: Rietveld condamnation considered as established by some more people

Bonjour Armel. In answer to your question "Where did they find the text of the judgement ?" please see: "The development of powder profile refinement at the Reactor Centre Netherlands at Petten" Bob van Laar and Henk Schenk https://scripts.iucr.org/cgi-bin/paper?ib5058 Van Laar worked at Petten w

Re: Rietveld website cancelled ?

Thanks Armel. Have a look also at the s-triazine paper. 30 years ago Pawley and I were determining structures of materials that are liquid at room temperature. I remember he was worried about liquid HCN on the French train. You might try that :-) ___

Re: Rietveld website cancelled ?

ssage du 29/08/18 12:33 > De : "Alan Hewat" > A : "Armel Le Bail" > Copie à : "rietveld_l@ill.fr" > Objet : Re: Rietveld website cancelled ? > > > A clear distinction having my complete agreement. (Armel) Ouf. Nous sommes d'accord enfin :-

Re: Rietveld website cancelled ?

;rietveld_l@ill.fr" > Copie à : > Objet : Re: Rietveld website cancelled ? > > > You dig ! Please stop digging Armel. Loaded guns, grave digging and religion are off limits. __ >    Dr Alan Hewat, NeutronOptics

Re: Rietveld website cancelled ?

> You dig ! Please stop digging Armel. Loaded guns, grave digging and religion are off limits. __ * Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE * +33.476.98.41.68 http://www.NeutronOptics.com/hewat ___

Re: Rietveld website cancelled ?

j" > A : "% MailingList Rietveld" > Copie à : elb...@jhu.edu > Objet : Re: Rietveld website cancelled ? > > It all depends on the definition. If/when we agree on the definition, there is usually no points for further arguing. Anyway we could call Relieved method a

RE: Rietveld website cancelled ?

our mind and a lot of chance- congratulations.   You dig.   Armel     > Message du 29/08/18 18:26 > De : "Von Dreele, Robert B." > A : "Larry Finger" , "Le Bail Armel" , "Toby, Brian H." > Copie à : "Rietveld_L@ill.fr" >

Re: Rietveld website cancelled ?

Was that Clint Eastwood? - Kurt From: rietveld_l-requ...@ill.fr on behalf of Le Bail Armel Sent: Wednesday, August 29, 2018 12:01:25 PM To: Rietveld_L@ill.fr Subject: Re: Rietveld website cancelled ? OK, seems that the SDPD book preface looks unclear to some

Re: Rietveld website cancelled ?

On 08/29/2018 02:01 PM, Le Bail Armel wrote: OK, seems that the SDPD book preface looks unclear to some. Western movies adepts well know that sentence : "You see, in this world there's /two kinds/ of /people/, my friend: /those/ with loaded /guns/, and /those/ who /dig/. /You dig/. .." Simil

Re: Rietveld website cancelled ?

those believing that the sense of the words "structure determination" and "structure refinement" are the same, and the others. You dig.   Best   Armel         > Message du 29/08/18 18:09 > De : "Larry Finger" > A : "Le Bail Armel"

Re: Rietveld website cancelled ?

It all depends on the definition. If/when we agree on the definition, there is usually no points for further arguing. Anyway we could call Relieved method a structure determination from powder data as long as it does not included solving structure (or as David elegantly put - true structural soluti

Re: Rietveld website cancelled ?

Absolutely important that people understand that the Rietveld method is structure refinement and not solution, but as Larry points out sometimes you can get a more out of it if you’re clever… and have no other choice! Here’s a second example: Stubbs et al., 2010, Uranyl phosphate sheet reco

RE: Rietveld website cancelled ?

. NB: this kind of thing has also happened more recently (see papers by Margiolaki, et al). Bob Von Dreele -Original Message- From: rietveld_l-requ...@ill.fr On Behalf Of Larry Finger Sent: Wednesday, August 29, 2018 11:10 AM To: Le Bail Armel ; Rietveld_L@ill.fr Subject: Re: Rietveld web

Re: Rietveld website cancelled ?

On 08/29/2018 04:15 AM, Le Bail Armel wrote: Hi, After the IUCr Monograph on Crystallography 13 (2002) entitled "Stucture Determination from Powder Diffraction Data" you may find in the preface : "Although the Rietveld method of structure refinement from powder diffraction data is often loos

Re: Rietveld website cancelled ?

ies that the structure is already determined (not always if you use ICDD), then if you wish, you may refine it by the Rietveld method     > Message du 29/08/18 12:35 > De : "Alan Hewat" > A : "Armel Le Bail" > Copie à : "rietveld_l@ill.fr" > Ob

Re: Rietveld website cancelled ?

> A clear distinction having my complete agreement. (Armel) Ouf. Nous sommes d'accord enfin :-) For Armel, here are a couple of examples of automatic indexing, search-match and structur

RE: Rietveld website cancelled ?

agreement.   Armel http://www.cristal.org/CAC-XX/maze.jpg http://www.cristal.org/CAC-XX/Rietveld.ppt     > Message du 29/08/18 10:14 > De : "May, Frank" > A : "Alan Hewat" , "rietveld_l@ill.fr" > Copie à : > Objet : RE: Rietveld website cancelled

RE: Rietveld website cancelled ?

To all: Initially I sent this to Alan who suggested I open discussion to the entire community. I've posted similar in past years and have been FLAMED. Please keep it civil. ;-) = As a long time practitioner of powder XRD (since 1972) I was there when the superconductor cr

Re: Rietveld website cancelled ?

> when the superconductor craze hit in the mid-1980s... it was recognized the Rietveld Method was useful only for REFINING structures which were generally accepted from single crystal x-ray analysis. That is an interesting observation, and it's a pity you didn't send it to the whole list because p

Re: Rietveld website cancelled ?

Good work Armel. Note that little is lost once it is posted to the WWW, since it is backed up in several places. The "WayBack Machine" is a good way of recovering historic web sites. The WayBack server is a bit slow, since it is supported only by donations and is probably in heavy demand - see: htt

Re: Rietveld

*> Argh ! Shame on us three ! * Yes, we went too far. Sorry Armel. But Robert only has to read the footer at the bottom of every post to find how to remove himself. __ * Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE * +33.476.98.41.68 http://

Re: Rietveld

not his 1967 or 1969 papers. Rietveld's real number of citations is probably closer to >40.000 than to 15.000. But you know that already...   Best,   Armel         > Message du 22/08/18 14:23 > De : "Alan Hewat" > A : "rietveld_l@ill.fr" > Copie

Re: Rietveld

*> Another example.. Loopstra, van Laar and Breed Physics Letters 26A(11) 1968, 526* (AleB) Examples are easy. In Gibaud, Le Bail and Bulou J. Phys. C: Solid State Phys. 19 (1986) 4623 "*...the Rietveld program modified by Le Bai

Re: Rietveld

Another example showing that Loopstra and van Laar (and Breed) recognized Rietveld as the main author as soon as 1968 in Physics Letters 26A(11) 1968, 526.   "The final proof that preferred orientation effects could in this way be removed from the results, was afforded by the excellent agreeme

[SUSPECTED SPAM] Re: Rietveld

>That is why I prefer to use Rietveld's original term "profile refinement" for >all kinds of powder pattern refinement, and reference Loopstra and Rietveld >(1969) instead of >just Rietveld (1969) In the Introduction of Loopstra and Rietveld (1969) they referred to the approach as "the profile

Re: Rietveld

Leonid. Rietveld's code is indeed a specific type of profile refinement. Structure parameters are refined to fit the observed profile intensities using a least squares code similar to that used to fit integrated Bragg intensities at Oak Ridge - ORFLS (1962). From 1961 profile refinement methods wer

Re: Rietveld

>Gauss and Legendre's work shows that science is not performed by individuals >in a vacuum. >Now we call it "Least Squares Refinement" and not "Gauss >Refinement". It seems that the basic collision is in the absence of strict and commonly accepted definition of the 'Rietveld Method' term. Does

Re: Rietveld

*> credit should be given to Rietveld for developing and distributing his software * No-one is disputing that, even if Rietveld himself never gave credit to anyone else. In Rietveld (1969) he merely `*thanks Drs B. O. Loopstra and B. van Laar for their suggestions and helpful criticism*'. Yet acc

RE: Rietveld

All the best Alan Coelho From: rietveld_l-requ...@ill.fr On Behalf Of Scott Speakman Sent: Wednesday, 22 August 2018 4:35 AM To: Rietveld_l@ill.fr Subject: RE: Rietveld It is interesting to read this conversation and to hear the various points of view. I have one point for co

Re: Rietveld

Scott. If for commercial reasons you don't wish to disclose the details of Panalytical's code, I suggest you reference "code based on the Rietveld code - Rietveld (1969) Reactor Centrum Nederland Report RCN-104 (which contains the original code). My version is on: http://www.ccp14.ac.uk/ccp/web-m

Re: Rietveld

Scott. If you use the code distributed by Rietveld, you should certainly acknowledge it as "the Rietveld program/code" as I did in my Harwell report 1973_The_Rietveld_Program_for_the_Profile_Refinement_of_ Neutron_Diffraction_Powder_Patterns_AERE_R7350-von_Dreele_annotations.pdf

RE: Rietveld

we want to do business: The value of Integrity - Code of Business Ethics<http://www.spectrisethics.co.uk/MAL/> From: rietveld_l-requ...@ill.fr On Behalf Of Le Bail Armel Sent: Tuesday, August 21, 2018 11:09 AM To: Rietveld_l@ill.fr Subject: Re: Rietveld The >1500 subscribers can vote...

Re: Rietveld

The >1500 subscribers can vote... :   https://doodle.com/poll/gh3v3nfhue599w23   Best,   Armel       > Message du 21/08/18 19:10 > De : "Alan Hewat" > A : "rietveld_l@ill.fr" > Copie à : > Objet : Re: Rietveld > > > As a matter

Re: Rietveld

*> As a matter of course we didn't took part in the discussi**on... * (Schenk) *> ...**people pretending now to speak in place **of Loopstra should stop to do so *(Le Bail) What a contrast of style and substance. Late believers are true believers, and Passion evicts Doubt. Seeking sanity, I refer

Re: Rietveld

Dear Rietvelders,   The last sentence of the van Laar & Schenk paper is  : "It seems to us justified to replace the name ‘Rietveld method’ in the future by the working title of the past: ‘profile method,’ or to honour the inventor by using ‘Loopstra method’." So, shame on Rietveld for having st

Re: Rietveld

ld_l-requ...@ill.fr> [mailto:rietveld_l-requ...@ill.fr <mailto:rietveld_l-requ...@ill.fr>] *On Behalf Of *Le Bail Armel *Sent:* Monday, 20 August, 2018 2:22 AM *To:* Rietveld_l@ill.fr <mailto:Rietveld_l@ill.fr> *Subject:* Re: Rietveld *>"...*/*the method did n

Re: Rietveld

lates/labs_3/images/new-tau-logo.png][image: > WAMRC-LOGO_new] > > > > *From:* rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] *On > Behalf Of *Le Bail Armel > *Sent:* Monday, 20 August, 2018 2:22 AM > *To:* Rietveld_l@ill.fr > *Subject:* Re: Rietveld > > &g

RE: Rietveld

ill.fr [mailto:rietveld_l-requ...@ill.fr] On Behalf Of Le Bail Armel Sent: Monday, 20 August, 2018 2:22 AM To: Rietveld_l@ill.fr Subject: Re: Rietveld >"...the method did not suddenly appear in a flash of inspiration of a single >person, but was the result of the work of three individuals

Re: Rietveld

Seems that Rietveld had not the same opinion and claimed for ideas too and possibly for mathematics as well. Best, Armel Armel, For the sake of the scientific exchange of ideas and facts, too bad that Dr. Rietveld is not alive. Regards, Miguel Delgado On 8/19/2018 6:21 PM, Le Bail Arm

Re: Rietveld

  >"...the method did not suddenly appear in a flash of inspiration of a single >person, but was the result of the work of three individuals... Loopstra, van >Laar and Rietveld.".   And more precisely :   " HS wrote in Dutch: ‘Loopstra had the idea that it should be better to use the whole

Re: Rietveld

> Seriously, HS really think that Hugo Rietveld had absolutely no idea, and then worked out mathematically nothing ? Armel, the vL&S paper doesn't say that Rietveld had no idea and contributed nothing. Please read the first line of the paper

Re: Rietveld

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 : le-bail.ar...@orange.fr > Copie à : "rietv

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

Re: Rietveld

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 di

Re: Rietveld

I am an interested reader of this thread, but have no direct knowledge of any of the history. I will add, however, a small point about Alan’s last note suggesting we could go back to calling the process “Profile Refinement” and dodge the personal attribution. My point is that naming things af

RE: Rietveld

t 2018 11:31 À : rietveld_l@ill.fr Objet : Re: Rietveld > ...your responsibility in establishing and approving the legend is quite high > Then times to destroy the legend come, and you want to be a part of it too, > apparently. As I get older, I believe less and less in legends. In the

Re: Rietveld

> ...your responsibility in establishing and approving the legend is quite high > Then times to destroy the legend come, and you want to be a part of it too, apparently. 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 the

Re: Rietveld

  >Probably, that's how legends begin.   Your presence on so many pictures together with Hugo Rietveld, suggests that your responsibility in establishing and approving the legend is quite high, between 30 and 60% maybe, but I recognize that Rwp is poorly satisfying for this fit. http://home.

Re: Rietveld

Armel's supervisor, Daniel Louer, made important contributions to the description of the line shape for profile refinement with x-rays, but that was 10 years later. His 1986 paper references Rietveld (1969) but uses a different type of profile refinement

Re: Rietveld

> * I remember that a Fortran version was in tests there (in Rennes in 1975-76), probably one of these 27 copies distributed by Hugo Rietveld himself to institutes all over the world.* Rietveld worked with neutron powder diffraction on magnetic and heavy metal oxides. An x-ray lab. in Rennes was p

Re: Rietveld

Hi,   Sorry for that blank email... Since times are to old stories about the Rietveld method, I first heard about it in 1975-76 during my "3ème cycle" thesis in D. Grandjean laboratory, Rennes, France, under the direction of D. Louër. The thesis was about profile-shapes broadening due to powder

Re: Rietveld

Hi,   >And no, Rietveld didn't invent an intensity extraction algorithm later used by >LeBail; Pawley's code predated LeBail, and both are more related to classical >ideas of peak extraction than to Rietveld.   I would personnally agree with Brian and reformulate : And yes, Rietveld invent

Re: Rietveld list subscription

> > That means after identifying impurity phases, we should keep cell > parameters and and all shape parameters fixed for impurity phases in > Rietveld refinement and refine only scale factor of these phases along with > main phase and then refine all cell parameters and and all shape parameters >

Re: Rietveld list subscription

> > I have prepared one sample which is showing some impurities. When I had > put one impurity phase and started refining it was showing NaN for chi. > What does that mean? and how to know for sure that the added phase is > present. You should send your query to the email address Rietveld_L@ill.f

Re: Rietveld refinement in TOPAS with parallel beam geometry

Sorry about the confusion on the instrument configuration. I am new to the field of x-ray diffraction. Hopefully this helps. The Bruker D8 uses reflection geometry and a THETA : THETA goniometer, where the x-ray source and detector can be move simultaneously on the arms of the goniometer. The x-ra

RE: Rietveld refinement in TOPAS with parallel beam geometry

Patrick, From: Patrick Price [patrickpric...@gmail.com] Sent: Friday, December 04, 2009 6:30 AM To: Rietveld_l@ill.fr Subject: Rietveld refinement in TOPAS with parallel beam geometry Since this is my first post I will start with a brief introduction. My n

Re: Rietveld Neophyte

Dear Dave, Actually, GSAS is not the best choice for crystal size analysis. There are specialized programs for this purpose such as MAUD for instance. If you can’t refine the Gaussian broadening parameters GU GV and GW you may get them from the refinement for a standard with big (>1000 nm) crys

Re: Rietveld with GSAS

Dear Mr Bhowmik, do not expect a massive metal ingot to be necessarily free of preferred orientation, in particular in presence of a dendritic microstucture. Thus it should be no surprise to observe wrong reflection intensities. Or did you manage to make a "powder" from your Cr based material?

Re: Rietveld: U,V,W

Hi, Self Citation: "NIST Standard Reference Materials for Characterization of Instrument Performance" Industrial Applications of X-ray Diffraction Ed by F. H. Chung & D. K. Smith, pp 903-917. A pdf is available; email to request. In this I outline how I use SRM 660 (it was 660 in 2000, then

Re: RE: Rietveld: U,V,W

synchrotron and neutron) can be found at http://mysite.du.edu/~balzar/s-s_rr.htm. Davor BalzarUniversity of Denverwww.du.eduwww.du.edu/~balzar - Original Message - From: "Maxim V. Lobanov" <[EMAIL PROTECTED]> Date: Sunday, November 30, 2008 10:37 pm Subject: RE: Riet

RE: Rietveld: U,V,W

Brian wrote: >U and W should be instrumental constants that will not change with >sample, >while V can have both an instrumental and a >residual stress component. Maxim wrote: >as far as I understand, the strain broadening term should have FWMM~theta >>dependence, i.e. Lorentzian Y in "standard"

RE: Rietveld: U,V,W

Toby [mailto:[EMAIL PROTECTED] Sent: Monday, December 01, 2008 5:21 AM To: May, Frank Cc: rietveld_l@ill.fr Subject: Re: Rietveld: U,V,W What is the correct procedure for refining U,V,W? It is my understanding that those parameters are a function of instrument geometry. Does one use a standard m

Re: Rietveld: U,V,W

Why my reply went to the author's personal mail box? I am very sorry for that. Now I am hunting for a standard reference material to determine the profile parameters of our instrument X'pert Pro. -- Mingtao Li State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Powe

Re: Rietveld: U,V,W

What is the correct procedure for refining U,V,W? It is my understanding that those parameters are a function of instrument geometry. Does one use a standard material to determine U,V,W and then fix their values for the instrument you're using?or do the values of U,V,W change dependin

RE: Rietveld Round Robin Test

Title: Message There were two papers resulting from a round robin on quantitative phase analysis sponsored by the IUCr Commission on Powder Diffraction. They are:-   (1)    I.C. Madsen, N.V.Y. Scarlet, L.M.D. Cranswick, T. Lwin, J. Appl Cryst. (2001) 34, 409-426 (2)    N.V.Y. Scarlet, I.C.

Re: rietveld refinement

>Going back to Leonid's question, well the answer is easy: check the >premises... the assumptions behind the use of the TCH function are >not >compatible with he presence of a lognormal distribution of domains. But the TCH function gave ALMOST PERFECT fit for the Size-Strain Round Robin profile

Re: rietveld refinement

just my 2 cents... > Could I be so stupid to say that such kind of works, including mine, are > nothing? following Nicolae, I should also add to the list myself as well as most people participating to the four editions of the size-strain conference/meeting/workshop and all participants to Dav

Re: rietveld refinement

Hi, At the moment there is development of a NIST Nanocrystallite Size Standard Reference Material (SRM1979). Jim Cline and I are working on this SRM. It will include two materials: (1) CeO2 with spherical crystallite shape and size distribution in the ~20nm size range (isotropic shape); (2) ZnO

Re: rietveld refinement

At least the anisotropic formalism by Popa (J. Appl. Cryst. (1998) 31, 176-180) has been used for anisotropic shape refinements using the MAUD Rietveld codes, on textured samples: Thin Solid Films 450, 2004, 216-221. daniel A 11:12 AM 11/22/04 +0300, vous avez écrit : > > It is also true that

Re: rietveld refinement

> > It is also true that no development has been done for anisotropy. Not yet! > > Well, if all previous works about trying to take account of size/strain > anisotropy in the Rietveld method are nothing yet, this allows to > close the discussion. Let us wait for really serious developments to > co

Re: rietveld refinement

Hi, With regards to size/shape/distribution analysis of line profiles, the papers by Armstrong et al. (2004a,b,c) discusses a Bayesian/Maximum Entropy method, that determines these quantities from the line profile data. This can also resolve bimodal distributions from line profile data. This

Re: rietveld refinement

Title: RE: rietveld refinement I'm afraid that you got the wrong end of the stick -I wasn't talking about the application of peak broadening to size distribution, I was commenting that determining crystallite shape is perfectly possible (some comments were flying that said other

Re: rietveld refinement

It is also true that no development has been done for anisotropy. Not yet! Well, if all previous works about trying to take account of size/strain anisotropy in the Rietveld method are nothing yet, this allows to close the discussion. Let us wait for really serious developments to come. Armel

Re: rietveld refinement

Title: RE: rietveld refinement    Doesn't help with a size distribution, as it only works well for a relatively monodisperse material - but it does work under some circumstances. Pam   I disagree, it works also for large dispersion. One example you can find in JAC (200

Re: rietveld refinement

> So I cannot let say that "Significantly different "physical" > size distributions could describe equally well the peak profile". > This is confusing. You may say that : significantly different > crystallite shapes could describe equally well the peak profile > in cubic symmetry. I am not sure th

Re: rietveld refinement

can anyone send me a soft copy of the following paper J. Appl. Cryst. (1978). 11, 50-55. thanks venkat +++ M Venkata Kamalakar Junior Research Fellow, S.N.Bose.National Centre for Basic Sciences, Block-JD, Sector-3, Salt Lake, Kolkata, Pin: 7

RE: rietveld refinement

can you please send me the soft copy of the paper you referred to. We don't have access to that journal... very much sincerely yours venkat From: Armel Le Bail <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Sent: Fri, 19 N

Re: rietveld refinement

Let me put a more particular question on the size estimation from Rietveld refinement. If we refined the size-broadening parameters P and X of the Thompson-Cox-Hastings function (as they are defined in J. Appl. Cryst. (2004) 911) and corrected them for the instrumental contribution, then can we say

RE: rietveld refinement

I'd have to disagree on this point - troublemaker I suppose! I've followed the work by Langford and Louer closely, and have successfully applied their techniques I do not understand on what point exactly you disagree. The cited paper about size effect in nickel hydroxyde is co-authored by D. Lo

RE: rietveld refinement

Title: RE: rietveld refinement   >There was a strong size anisotropy. The X-ray study cannot >gives the shape (you see that I agree with you on that point), >an electron microscopy study showed that the coherently >diffracting domains are plate-like crystallites aggregated along

Re: rietveld refinement

Small error, sorry, three of the possible arrangement were : |--| | |--| | | |--|--| |--|--|--|--| |--| | | |--| | |--|--| | |--|--|--|--| |--| | | |--| | | | | |--| |--| |--| |--|

Re: rietveld refinement

What we see in diffraction is the column lengths (volume & area averaged) and the classics were not full ignoring the shape and radius (radii) distribution(s). Nicolae Popa (Mister, Messieur, Don, Dom, etc.) Of course I agree with you that completely different shapes may correspond to the same dis

Re: rietveld refinement

> > >The diffraction alone can not decide. Significantly different "physical" > >size distributions could describe equally well the peak profile > >(J.Appl.Cryst. v35 (2002) 338-346 - self citation too). > >Nicolae Popa > > Looking at your figures 6b1 and 6b2, I measure how we > differ on the sens

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