Introduction

1999-06-11 Thread Leonid Solovyov
Dear All, As a new member of the list let me introduce myself. My name is Leonid Solovyov. I am a researcher at the Institute of Chemistry and Chemical Technology of the Russian Academy of Sciences. Current activities: Determination and refinement of the crystal structures of inorganic

Re: more questions about the Scherrer formula

2000-11-29 Thread Leonid Solovyov
to use in the Sherrer formula. I also hope that the Size-Strain Round Robin results will suggest the best way of obtaining the size-strain parameters from Rietveld refinement. Best, Leonid Solovyov __ Do You Yahoo!? Yahoo! Shopping - Thousands

Re: more questions about the Scherrer formula

2000-11-30 Thread Leonid Solovyov
Dear Koray, There is no need to ask me for posting you message to the Rietveld list. If you send it to [EMAIL PROTECTED] it is automatically there. Best, Leonid Solovyov __ Do You Yahoo!? Yahoo! Shopping - Thousands of Stores. Millions of Products. http://shopping.yahoo.com/

Re: Fractional coordinates

2001-01-08 Thread Leonid Solovyov
, Y.Wang., J.Am.Chem.Soc., 1991, V.113, P.2328. (disordering is detected even at this low temperature) Best, Leonid Solovyov __ Do You Yahoo!? Yahoo! Photos - Share your holiday photos online! http://photos.yahoo.com/

Size distribution from Rietveld refinement

2004-11-22 Thread Leonid Solovyov
Dear Rietvelders, Despite the heated discussion of the problem, the initial question, which, actually, concerned the size distribution from Rietveld refinement, seems to be unsettled. Can we derive ANY information on the crystallite size distribution (based on sensible assumptions) from the

RE: Size distribution from Rietveld refinement

2004-11-22 Thread Leonid Solovyov
Thank you, Davor! Despite several HOWEVERs in your message it clarifies the situation. Best wishes, Leonid __ Do you Yahoo!? Meet the all-new My Yahoo! - Try it today! http://my.yahoo.com

Re: Size distribution from Rietveld refinement

2004-11-24 Thread Leonid Solovyov
actually I implemented the size and strain distributions (both) in my Rietveld code (Maud) and I demoed it in Praha beginning of September Good news! I look forward to see the program. Which profile function do you use for size distribution analysis? Hopefully not TCH pseudo-Voigt... Regards,

RE: [sdpd] Derivative Difference Minimization

2005-01-21 Thread Leonid Solovyov
Alan wrote: First impressions - What a nifty idea. Haven't given thought to all of the ramifications but it certainly does seem to have merits. Cant wait to analyze it myself; put it through its paces so to speak. Thanks, Alan, for such an impressive comment. DDM really makes Life easier

Re: new BGMN/BGMNwin

2005-02-19 Thread Leonid Solovyov
datasets. Best, Leonid Solovyov __ Do you Yahoo!? Read only the mail you want - Yahoo! Mail SpamGuard. http://promotions.yahoo.com/new_mail

Re: Experimental background!

2005-02-24 Thread Leonid Solovyov
Nanocrystalline phase in films deposited on silica glass substrate: After normalization and subtraction of experimentally measured substrate pattern, the Rietveld fitting (GSAS) of the Nanocrystalline phase becomes worst than the case of mathematically modelled background. Which is the

RE: Size Strain In GSAS

2005-03-29 Thread Leonid Solovyov
done several times... With a whole pattern approach and working directly with the profile arising from a distribution of domains, in most cases you're able to recostruct the original distribution without making any assumption on its functional shape (after all, most of the information to do

RE: Size Strain In GSAS

2005-03-30 Thread Leonid Solovyov
Dear Matteo, Thanks for the exercise. From pseudo-Voight fitting I have got Dv=33A, Da=23A, which gives the average size D=21A and the relative dispersion c=0.28 (c = [sigmaD/D]^2). However, I suspect that the actual values you used for the simulation were D~30A and c~0.25. Do I win the F1 GP?

DDM for academicians

2005-03-31 Thread Leonid Solovyov
Dear All, I am pleased to inform you that an academic version of DDM is available now at reduced price. This version is very elaborate, sophisticated and difficult to use. It is specially designed for smart, wise and highly experienced academicians. The current academic price is 1 Russian

Re: DDM for academicians

2005-04-01 Thread Leonid Solovyov
See a large deposit of such smart, wise and highly experienced french academicians in science at : http://www.academie-sciences.fr/ A search with the keyword Rietveld gives there only one link: http://www.academie-sciences.fr/publications/lettre/pdf/lettre_5.pdf showing that we have to be

Re: Size Strain in GSAS

2005-04-13 Thread Leonid Solovyov
8. The simple modified TCH model (triple-Voigt), used in most major Rietveld programs these days, is surprisingly flexible. It works well for most of the samples (super-Lorentzian is an example when it fails, as well as many others, but this is less frequent that onewould expect) and gives

RE: Size Strain in GSAS

2005-04-14 Thread Leonid Solovyov
It was shown in paragraph 6 of JAC 35 (2002) 338-346 that size-broadened profiles given by both lognormal and gamma distributions can be approximated by a weighted sum of Lorentz and Gauss functions for a broad range of distribution dispersions. Besides, round robins can sometimes be long

Re: Size Strain in GSAS

2005-04-14 Thread Leonid Solovyov
It is not exact what you say, ty ploho cital. 6 7 from JAC 35 (2002) 338-346 gives the size profile - formulae (15a) combined with (21,22) or (20a) combined with (23,24). If you look carefully, these profiles are approximated by pseudo-Voigt or sums of 2 or 3 Lorentzians. These

DDM update at New Address

2005-04-16 Thread Leonid Solovyov
Dear colleagues: An update of DDM program is available at new address: http://icct.krasn.ru/eng/content/persons/Sol_LA/ddm.html which is hoped to be permanent. The changes made in this version are: 1. The 4-th rank tensor for anisotropic strain broadening is added. 2. The use of anisotropic

Re: Size Strain in GSAS

2005-04-16 Thread Leonid Solovyov
Indeed you missed something. I presume you have the paper. Then, take a look to the formula (15a). This is the size profile for lognormal. There is the function PHI - bar of argument 2*pi*s*R. Replace this function PHI - bar from (15a) by the _expression (21a) with the argument x=2*pi*s*R.

Re: Size Strain in GSAS

2005-04-17 Thread Leonid Solovyov
Dear Nicolae, I will comment only upon your last statement because the limitations of your modeling are clear. Well, I don't know where from you taken these formulae but I observe that for spheres of equal radius, then zero dispersion, you have: sigma(D)=5D/4, different from zero! First

Re: Ranking of solutions in DICVOL04

2006-06-22 Thread Leonid Solovyov
by further successful structure determination. Leonid Solovyov __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

Re: FullProf: sample transparency (SYSIN) and absorption (muR)

2006-11-30 Thread Leonid Solovyov
Dear Irina, As far as I know the parameters Sysin and muR in Fullprof are independent and can be used separately, while this is not reasonably logical. Best regards, Leonid Original message === Good evening, I have two questions for FullProf users: 1. If I want to refine the

Re: Le Bail vs Rietveld for crystallite size and cell parameters?

2007-11-06 Thread Leonid Solovyov
, besides, an estimation of the uncertainties. Regards, Leonid Solovyov Dear All, I was wondering if there are any advantages of using Rietveld vs Le Bail refinements when crystallite size and cell parameters are the only variables of interest? Thank you, Sergey

RE: Amorphous content

2007-11-16 Thread Leonid Solovyov
For quantitative analysis the flat-plate transmission geometry is much more preferable as it is free of the microadsorbtion problem. Of course, resolution is not so easily achievable in this geometry, but one may use synchrotron at last. Best regards, Leonid Solovyov Thanks Reinhard and all

Re: advice on new powder diffractometer

2008-02-17 Thread Leonid Solovyov
to reduce the asymmetry. Additionally, the secondary monochromator for X’Celerator or PIXcel detectors makes the peaks even more symmetric as it suppresses the axial divergence. Leonid Solovyov Be a better

Re: advice on new powder diffractometer

2008-02-18 Thread Leonid Solovyov
Yes it is mainly down to the Soller slits, there was a very large thread on soller slits somewhere in the Rietveld archives about this discussion. I think the down side of changing the soller slits is a move away from the optimum FWHM that can be obtained? Changing sollers from 0.04 rad to

RE: advice on new powder diffractometer

2008-02-19 Thread Leonid Solovyov
It seems to me that if there is no internationally accepted definition of signal to noise ratio in powder diffraction, then let me suggest that this forum might be a way to define it once and for all. How about this? SNR = (P-B)/SQRT(B). Of course this would only

Re: Beginer problems, difficulty charecterizing our diffractometer...

2008-09-17 Thread Leonid Solovyov
Dear Blaise, The strong peak asymmetry may result from high-divergence Soller slits installed in your instrument. You may consider using sollers of lower divergence that normally allows easier peak shape approximation and, besides, increases the resolution (at the expense of intensity, of

Re: Beta iso

2008-09-23 Thread Leonid Solovyov
Dear Mario, Negative isotropic displacement parameters are physically meaningless and are indicative of problems in either the model or the data (or both). Possible reasons: low sensitivity of refinement to displacement parameters due to insufficient data quality; incorrect refinement of peak

Re: Question on QPA - Amorphous/crystalline mix

2008-10-14 Thread Leonid Solovyov
Dear Lee, Your calculations are correct provided the allowances for microabsorption and other effects were made properly. Regards, Leonid --- On Tue, 10/14/08, Lee Gerrard [EMAIL PROTECTED] wrote: From: Lee Gerrard [EMAIL PROTECTED] Subject: Question on QPA - Amorphous/crystalline mix To:

Re: question on size-strain analysis

2008-10-21 Thread Leonid Solovyov
Hi Nicolae, Nice to hear from you! I couldn't help noting that in reality your emergence in the Rietveld list is similarly rare as the narrow size distribution :-). Instrumental problems are far more regular. Best wishes, Leonid *** Leonid

Re: GSAS: Microstrain parameters in rhombohedral SGs

2008-10-26 Thread Leonid Solovyov
Dear Franz, The symmetry-specific expressions for the Shkl tensor are given in GSASManual.pdf pages 150-151. Regards, Leonid *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology K. Marx av., 42 660049, Krasnoyarsk Russia

Re: Quantitative analysis

2008-10-28 Thread Leonid Solovyov
Dear Mario, One more possible problem of applying preferred orientation corrections in QPA is that not all of them are normalized. For example, the March-Dollase correction is normalized and can be applied safely, but the Rietveld-Toraya correction is inapplicable to QPA as it does not

RE: question on size-strain analysis

2008-11-13 Thread Leonid Solovyov
Dear Maxim, Yes, these calculations can be done for TCH pV relatively simply (not “really simply” :-). The crystal size estimations from the refined parameters of TCH pV are included, for instance, into the DDM program [www.icct.ru/eng/content/persons/Sol_LA/ddm.html] and the formulae are

RE: question on size-strain analysis - question for Fullprof users

2008-11-13 Thread Leonid Solovyov
Dear Maxim, Actually, there are no standard notations for these parameters of TCH pV. In different programs they are designated differently. Regards, Leonid --- On Thu, 11/13/08, Maxim V. Lobanov [EMAIL PROTECTED] wrote: From: Maxim V. Lobanov [EMAIL PROTECTED] Subject: RE: question on

DDM update

2008-11-27 Thread Leonid Solovyov
is added that is chosen now by IWGHT flag. 3. New asymmetry parameter P2 responsible for the lattice-gradient effect is added. Other changes are listed in history.txt Best regards, Leonid Solovyov *** Leonid A. Solovyov Institute of Chemistry

Re: I am a newcome, how can I begin my rietveld refinement analysis

2008-11-29 Thread Leonid Solovyov
At the initial stage you don’t need precise values of U, V, and W. You may set U=0, V=0, and W equal to the squared FWHM of the highest peak.   Leonid *   Leonid A. Solovyov   Institute of Chemistry and Chemical Technology   660049,

RE: Rietveld: U,V,W

2008-11-30 Thread Leonid Solovyov
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 (GSAS)

Re: Can anybody do me a favor to refine my Y2O3?

2008-12-05 Thread Leonid Solovyov
Dear Li, I don't use GSAS, but I refined your data using the DDM program that gave nearly perfect fit. The DDM parameters file is attached and the program is freely available from http://www.icct.ru/eng/content/persons/Sol_LA/ddm.html or http://www.geocities.com/l_solovyov/ddm.html I must

Re: calculation of VWDS and SWDS from distributions?

2008-12-08 Thread Leonid Solovyov
Dear Maxim, The formulae Dv=3mu_4/2mu_3 Da=4mu_3/3mu_2 are valid for spherical crystallites only. Accordingly, in the expression mu_i=Int[0, Infinity]{x^i*p(x)dx} x should be the radius of spherical crystallite, but not “particle size”. Best regards, Leonid

RE: calculation of VWDS and SWDS from distributions?

2008-12-15 Thread Leonid Solovyov
Dear Maxim, In the expression Dv=3mu_4/2mu_3 mu is related to the crystal RADIUS distribution, but in Lv=3mu_4/4mu_3 mu is related to the crystal DIAMETER distribution As for the instrumental and strain contributions, they may be correctly allowed for along with the size effect using the TCH

Re: error in peak positions that is linear in theta

2009-01-08 Thread Leonid Solovyov
Dear Kurt, It seems that the problem is in wrong sample-to-detector distance which results in the nearly linear angular dependence of the peak displacement. Regards, Leonid * Leonid A. Solovyov Institute of Chemistry and Chemical

Re: cRs

2009-03-04 Thread Leonid Solovyov
Maxim V. Lobanov wrote: However, some Rietveld programs do not have good selection of BG functions, and it is sometimes problematic to correctly fit the BG - so, I think in this case careful BG removal would be the only option. Not the only option... You have an option to forget about the

DDM update to 1.6

2009-03-16 Thread Leonid Solovyov
Dear All, The DDM program is updated to version 1.6 at: http://www.geocities.com/l_solovyov/ddm.html The main changes are: 1. Over 100 additional space group settings are added, covering all the variants found in the ICSD. 2. The convolution interval assignment procedure is modified. It

Re: DDM update to 1.6

2009-03-16 Thread Leonid Solovyov
It seems that the DDM-page traffic was overloaded at geocities today At the main page http://www.icct.ru/eng/content/persons/Sol_LA/ddm.html it will be updated tomorrow. Sorry for the inconvenience! ***  Leonid A. Solovyov  

Unsettling news from PANalytical

2009-03-31 Thread Leonid Solovyov
Dear Rietveldians and SDPDists! According to unsettling news from PANalytical the basic laws of the universe SUBJECT TO ALTERATIONS WITHOUT NOTICE (probably due to the global crisis). See the document: http://l-solovyov.narod.ru/subject_to_alterations.pdf and take care! Leonid

Re: [ML] Unsettling news from PANalytical

2009-04-01 Thread Leonid Solovyov
Not yet, but if PANal helps me... ;-) --- On Wed, 4/1/09, martijn.fran...@panalytical.com martijn.fran...@panalytical.com wrote: From: martijn.fran...@panalytical.com martijn.fran...@panalytical.com Subject: Re: [ML] Unsettling news from PANalytical To: Leonid Solovyov l_solov...@yahoo.com Cc

Re: [ML] Unsettling news from PANalytical

2009-04-01 Thread Leonid Solovyov
Date: Wednesday, April 1, 2009, 9:58 AM The designer of the Universe is not obligatory chemist.  - Original Message - From: martijn.fran...@panalytical.com To: Leonid Solovyov l_solov...@yahoo.com Cc: rietveld_l@ill.fr Date: 2009-04-01 15:35:23 Subject: Re: [ML] Unsettling news from

DDM update 1.7

2009-05-18 Thread Leonid Solovyov
Dear All, A new version (1.7) of the Derivative Difference Minimization program DDM is available at: www.icct.ru/Eng/Content/Persons/Sol_LA/ddm.html mirrors: l-solovyov.narod.ru/ddm.html www.geocities.com/l_solovyov/ddm.html The main changes: 1. A bug in the hexagonal lattice refinement is

Re: about background substraction

2009-05-19 Thread Leonid Solovyov
Dear Wahyu, You may do quantitative analysis without background refinement or subtraction using DDM: www.icct.ru/Eng/Content/Persons/Sol_LA/ddm.html Regards, Leonid --- On Tue, 5/19/09, wahyu bambang wahy...@gmail.com wrote: From: wahyu bambang wahy...@gmail.com Subject: about background

RE: LP factor in the Rietveld refinement

2009-07-22 Thread Leonid Solovyov
Dear Peter, Of course the LP correction can't be sample-dependent and for your configuration LP=0 should be Ok for all samples. It seems that you have an intensity loss at high-angles that may be partly compensated by LP=90. Possible reason may be in a misalignment of the anti-scattering

RE: LP factor in the Rietveld refinement

2009-07-23 Thread Leonid Solovyov
alor...@unex.es Subject: RE: LP factor in the Rietveld refinement To: Leonid Solovyov l_solov...@yahoo.com Cc: rietveld_l@ill.fr Date: Thursday, July 23, 2009, 7:00 AM Dear All, In this scenario, which should be the number for LP in Topas if ones has a D8 with a primary monochromator

Re: LP factor in the Rietveld refinement

2009-07-25 Thread Leonid Solovyov
As far as I know, for X-ray mirrors the LP angle is near zero. Leonid *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660049, K. Marx 42, Krasnoyarsk , Russia www.icct.ru/eng/content/persons/Sol_LA

Re: Rietveld Neophyte

2009-10-23 Thread Leonid Solovyov
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)

Re:

2009-11-05 Thread Leonid Solovyov
Dave, If you can send also the data-file you may increase a chance to get further feedback. Leonid *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660049, K. Marx 42, Krasnoyarsk, Russia

Re: Configuration of PANalytical X'pert Pro

2009-11-27 Thread Leonid Solovyov
Dear Alexandra, The term “standard configuration” is rather indefinite since PANal has a lot of various configurations and accessories. The most straightforward option for reducing the low-angle background is the programmable divergence and anti-scatter slits. For a fixed slit system the

RE: Configuration of PANalytical X'pert Pro

2009-12-01 Thread Leonid Solovyov
Dear Alexandra, The 1/4 divergence and 1/2 anti-scatter slits are narrow enough to give a reasonably low background after 5 degrees 2Theta. First I would check that the background is not related to the sample itself. It may be done by measuring an empty sample holder. The background may also

Re: calcul of a vector indices

2010-01-15 Thread Leonid Solovyov
Dear Teresa, The nearest Miller indexes of planes in Mercury are displayed in Display - More information - Planes list Best regards, Leonid *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660049, K. Marx 42, Krasnoyarsk,

Re: Microstructural analysis by fullprof

2010-02-20 Thread Leonid Solovyov
Dear Alice, The Gaussian component may be related to either the instrumental broadening or a narrow crystal size distribution. In the case you described I see two possible options: 1) You don’t properly take into account the instrumental contribution which is most pronounced for big

DDM-GUI beta version

2010-03-19 Thread Leonid Solovyov
Dear All, A beta-version of GUI for the Derivative Difference Minimization program DDM is available from http://sites.google.com/site/ddmsuite and http://www.icct.ru/eng/content/persons/Sol_LA/ddm.html Many thanks to Alexandr Zaloga, Yaroslav Yakimov and Igor Yakimov from the Siberian federal

Re: [sdpd] Re: Are restraints as good as observations ?

2013-07-31 Thread Leonid Solovyov
/solovyovleonid *** From: Jonathan WRIGHT wri...@esrf.fr To: Leonid Solovyov l_solov...@yahoo.com Cc: s...@staffmail.ed.ac.uk s...@staffmail.ed.ac.uk; rietveld_l@ill.fr rietveld_l@ill.fr; s...@yahoogroups.com s

Re: [sdpd] Re: Are restraints as good as observations ?

2013-07-31 Thread Leonid Solovyov
Technology 660049, K. Marx 42, Krasnoyarsk, Russia http://sites.google.com/site/solovyovleonid *** From: Jonathan WRIGHT wri...@esrf.fr To: s...@yahoogroups.com Cc: Leonid Solovyov l_solov...@yahoo.com; rietveld_l

Re: [sdpd] Re: Are restraints as good as observations ?

2013-07-31 Thread Leonid Solovyov
All Rietvelders (included me) are certainly trying a completely free refinement before to decide or not to use selected restraints. About All I certainly doubt. Am I especially scrutinized? I feel more and more uncomfortable about such verifications of everything I do: I believe that one

Re: [sdpd] Re: Are restraints as good as observations ?

2013-07-31 Thread Leonid Solovyov
The problem with powder diffraction measurements is that they often leave us information-starved. Certain informational starvation is a feature of any experimental technique and powder diffraction is not a marginal one in this respect. Starvation, however, is not an absolution for artificial

Re: [sdpd] Re: Are restraints as good as observations ?

2013-07-31 Thread Leonid Solovyov
Instead, I adopted the restraint/constraint system as soon as some distances went stranges. Yes, fear, fear to be personnally attacked again that way.   For me restraints are much more frightful ;-(: http://www.google.com/search?q=restraints While for some sort of people they may be thrilling.  

Re: [sdpd] Re: Are restraints as good as observations ?

2013-08-01 Thread Leonid Solovyov
Leonid, I suggest you to try K4P2O7 - synchrotron data, space group P61 - for which I had to put distance restraints on the three P2O7 independent groups - Powder Diffraction, 28, 2-12, 2013   Done without restraints: http://sites.google.com/site/ddmsuite/tutorials/K4P2O7-DDM.cif Only Biso of

Re: [sdpd] Re: Are restraints as good as observations ?

2013-08-01 Thread Leonid Solovyov
What information capacity ? The fact is that imposing the expected values you obtain a similar fit. This tells you that you cannot discuss your unrestrained information, because it is unreliable. Information is something you may discuss reliably. The only possible discussion about P3-O14 =

Re: [sdpd] Re: Are restraints as good as observations ?

2013-08-01 Thread Leonid Solovyov
To: Leonid Solovyov l_solov...@yahoo.com; s...@yahoogroups.com s...@yahoogroups.com Cc: rietveld_l@ill.fr rietveld_l@ill.fr Sent: Friday, August 2, 2013 6:59 AM Subject: RE: [sdpd] Re: Are restraints as good as observations ? At the end it is all wrong as we don’t refine individual electrons

Re: [sdpd] Re: Are restraints as good as observations ?

2013-08-02 Thread Leonid Solovyov
I mean, Leonid refuse to see any reliability limit to the powder results. Absurdity does not exist at all for him (with the exception of mine apparently). The difference between us is that I am happy with 1.634(2) but already think that soft restraints are clearly needed when I have 1.72(3).

Re: [sdpd] Re: Are restraints as good as observations ?

2013-08-02 Thread Leonid Solovyov
remember the previous discussion at the  Rietveld list where he claimed that all H can be seen and refined independently, always. Absurd - never said so. From absurdity and crimes we arrived at falsifications? Not sure that your young students have received a complete formation if they have to

Re: [sdpd] Re: Are restraints as good as observations ?

2013-08-02 Thread Leonid Solovyov
? At 03:04 02/08/2013 -0700, Leonid Solovyov wrote: remember the previous discussion at the Rietveld list where he claimed that all H can be seen and refined independently, always. Absurd - never said so. From absurdity and crimes we arrived at falsifications? Below are the unfalsified words

Unrestrained SDPD future

2013-08-09 Thread Leonid Solovyov
Dear colleagues, Since the restrained SDPD future has been announced in the respective list without a chance to go back: http://tech.groups.yahoo.com/group/sdpd/message/3016 It's my turn to put forward an alternative unrestrained variant that seems a bit more interesting and not so hopeless,

Re: [sdpd] Unrestrained SDPD future

2013-08-09 Thread Leonid Solovyov
*** From: Leonid Solovyov l_solov...@yahoo.com To: s...@yahoogroups.com s...@yahoogroups.com Cc: rietveld_l@ill.fr rietveld_l@ill.fr Sent: Friday, August 9, 2013 2:22 PM Subject: [sdpd] Unrestrained SDPD future   Dear colleagues, Since the restrained SDPD future has been announced

Re: [sdpd] Bethanechol chloride : new single crystal results

2013-09-04 Thread Leonid Solovyov
Dear Armel, From the comparison of your distances and angles with the single-crystal ones, two obvious conclusions can be drawn: 1) Applying a simplified refinement model one can't expect accurate results 2) Uncertainty estimations in Rietveld programs are inadequately optimistic Here you may

Re: [sdpd] Bethanechol chloride : new single crystal results

2013-09-04 Thread Leonid Solovyov
A good chemist is able to destroy any SDPD future. Unrestrained future can't be destroyed. Being restrained, however, it destroys itself. The low-temperature single-crystal refinement doesn't eliminate the necessity for accurate room-temperature structural data that may be required for QPA,

Re: [sdpd] Bethanechol chloride : new single crystal results

2013-09-05 Thread Leonid Solovyov
Easy to find a lot of published restrained refinements. Easy to restrain, thus easy to find - nobody doubts. Sorry to destroy your unrestrained future. Don't worry: even Armel Le Bail can't destroy the future. Unrestrained refinement is possible yet for such ugly data:

Re: phase id for Friday refreshment

2013-10-25 Thread Leonid Solovyov
  *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660049, K. Marx 42, Krasnoyarsk, Russia http://sites.google.com/site/solovyovleonid *** On , Leonid Solovyov l_solov...@yahoo.com wrote: Dear Mikko, Your XRD pattern

Re: X-ray diffraction laboratory manager position

2013-12-05 Thread Leonid Solovyov
If PhD is required even for politicians, why technicians should be the minorities?   http://www.dw.de/tempting-phds-lead-politicians-into-plagiarism/a-16595782   *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660049, K.

Re: X-ray diffraction laboratory manager position

2013-12-06 Thread Leonid Solovyov
If scientists aren't supposed to know how to use screwdrivers, then the position definitely requires PhD ;-)   *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660049, K. Marx 42, Krasnoyarsk, Russia

Re: X-ray diffraction laboratory manager position [faked-from]

2013-12-06 Thread Leonid Solovyov
Why are there so few job opportunities for people who have a Masters degree?   ‘Cause it’s well known that PhDs do much better than non-PhDs ;-) Imposing PhD-requirements for such positions is risky, in fact, as a real successful PhD won’t be interested and they will get a politician instead.

Re: X-ray diffraction laboratory manager position

2013-12-07 Thread Leonid Solovyov
PhDs find more convenient to use a phone rather than a screwdriver Phone instead of screwdriver??? It must be a SMARTphone I guess… *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660049, K. Marx 42, Krasnoyarsk, Russia

Re: quantitative analysis - perovskites - preferred orientation

2014-02-06 Thread Leonid Solovyov
Dear Lukasz, First of all, in the majority of Rietveld programs the uniaxial preferred orientation (such as [100]) can not be handled adequately for cubic systems since the programs normally generate only one symmetrically equivalent hkl for a diffraction peak. In DDM, for such cases, I

Re: on high pressure data indexing and unit cell reduction

2014-03-03 Thread Leonid Solovyov
Unit cell standardization may be done in VESTA http://jp-minerals.org/vesta Load a CIF to VESTA and go to Utilities-Standardization of Crystal Data then File-Export Data   *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology

a 32 years story involving Pawley and Le Bail methods + DFT

2014-03-04 Thread Leonid Solovyov
Dear Colleagues,   Since the SDPD group apparently disappeared from Yahoo, I’m answering a query raised there some time ago using this yet unrestrained list. The query record is attached after the message.  The crystal structure solution of decafluorocyclohexene announced in the SDPD list as “a 32

Re: PO corrections in trigonal space groups?

2014-03-25 Thread Leonid Solovyov
Dear Mathew, The 104 plane in calcite corresponds to the most intense reflection that is related, in turn, to the best spacing or separation between atomic layers along which the cleavage may occur. This is not a strict rule, of course, as real cleavage planes may be different depending on

Re: Hot stage data inconsistencies

2014-04-01 Thread Leonid Solovyov
Our current dilemma is that our data collected at 400C and below deviates from a smooth linear trend, and this is not expected. In oxide perovskites the oxygen vacancies may be stabilized below the temperature threshold at 400-500C. It can be detected by DSC measurements.

Re: Reference Intensity Ratio of clay minerals

2014-04-02 Thread Leonid Solovyov
The Rietveld-QPA doesn’t require RIR, as the peak intensities of phases are calculated from the structure models. What do you mean under “doing Rietveld” and ”structural files” in your case?   *** Leonid A. Solovyov Institute of Chemistry and

Re: Reference Intensity Ratio of clay minerals

2014-04-02 Thread Leonid Solovyov
: Chrysochoou, Maria mchry...@engr.uconn.edu To: Leonid Solovyov l_solov...@yahoo.com Cc: Sent: Wednesday, April 2, 2014 5:07 PM Subject: RE: Reference Intensity Ratio of clay minerals I am using Jade to do Whole PAttern Fitting, which utilizes structural models like you said. Even though you

Re: Stacking faults and antiphase boundary

2014-04-02 Thread Leonid Solovyov
if I don't have all that time to maintain a fully featured site always updated to the last news. Best regards,   Luca Lutterotti On Jun 26, 2013, at 10:07 AM, Leonid Solovyov l_solov...@yahoo.com wrote: Dear David, As I may guess from the microstructural options in Maud, the Warren model

Re: Stacking faults and antiphase boundary

2014-04-03 Thread Leonid Solovyov
, Akademgorodok 50/24, Krasnoyarsk, Russia http://sites.google.com/site/solovyovleonid *** - Original Message - From: Luca Lutterotti luca.luttero...@ensicaen.fr To: Leonid Solovyov l_solov...@yahoo.com Cc: Sent: Thursday, April 3, 2014 6:33 PM

Re: Stacking faults and antiphase boundary

2014-04-04 Thread Leonid Solovyov
***   - Original Message - From: Luca Lutterotti luca.luttero...@ing.unitn.it To: Leonid Solovyov l_solov...@yahoo.com Cc: Luca Lutterotti luca.luttero...@ensicaen.fr; rietveld_l@ill.fr rietveld_l@ill.fr Sent: Friday, April 4, 2014 1:20 PM Subject: Re: Stacking faults

Re: Stacking faults and antiphase boundary

2014-04-06 Thread Leonid Solovyov
: Luca Lutterotti luca.luttero...@ing.unitn.it To: Leonid Solovyov l_solov...@yahoo.com Cc: Luca Lutterotti luca.luttero...@ensicaen.fr; rietveld_l@ill.fr rietveld_l@ill.fr Sent: Friday, April 4, 2014 1:20 PM Subject: Re: Stacking faults and antiphase boundary Sorry Leonid, but here we

Re: Stacking faults and antiphase boundary

2014-04-07 Thread Leonid Solovyov
ice example is reported in some more depth in  PNAS 109 (2012) 21259 Best regards Andreas   On 07.04.2014 09:05, Jonathan WRIGHT wrote: On 06/04/2014 08:06, Leonid Solovyov wrote: The faulting model in DDM gives nearly perfect agreement with the experiment: http://sites.google.com/site

Re: Phase volume fraction

2014-05-02 Thread Leonid Solovyov
Dear Apu, If you use the Rietveld-based QPA you may assess the detection limit for a phase from the estimated standard uncertainty of its weight (or volume) fraction. In this case one should also take into account the fact that the Rietveld standard uncertainties of QPA are underestimated

Re: Discrepancy in the atomic coordinates of two isostructural compounds

2014-06-19 Thread Leonid Solovyov
If you don’t refine the anisotropic displacement parameters, this ”splitting” of Fe/Zn position may merely compensate the luck of anisotropic displacements in the model.   *** Leonid A. Solovyov Institute of Chemistry and Chemical Technology

Re: question on stacking faults

2014-10-03 Thread Leonid Solovyov
Dear Angel, The broadening due to stacking faults is structure-dependent, so the expressions derived for HCP structures are applicable only to the specific faults in close-packed atomic arrays.A general model applicable to any structure is described in J Appl Cryst (2000) 338 and implemented in

Re: isotropic displacement parameter

2014-11-02 Thread Leonid Solovyov
The reason may be in the absorption (as noted by Alan Hewat) for capillary samples or in the surface roughness effect for flat samples. ***Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660036, Akademgorodok 50/24,

Re: Determination of Microstrain using MAUD

2015-03-21 Thread Leonid Solovyov
Dear Lennart, In the microstructure analysis you aim at, one should take into account different contributions to the peak broadening: instrumental, crystal size, microstrain, and stacking faults. Using only two reflections (111 and 200) one can not allow for all these contributions

Re: 3D powder averaging...

2015-05-11 Thread Leonid Solovyov
Dear Jon, Considering the link you gave: http://www.buzzfeed.com/lukelewis/what-british-people-say-versus-what-they-mean I think it would be relevant to clarify your sentence: ‘Choosing to single out individual publications for public abuse on a mailing list is a bit of a shame’. I believe

Re: On the “crystallographic good practices”

2015-05-10 Thread Leonid Solovyov
*** - Original Message - From: nicp...@infim.ro nicp...@infim.ro To: Leonid Solovyov l_solov...@yahoo.com Cc: Lista Rietveld rietveld_l@ill.fr Sent: Sunday, May 10, 2015 3:20 PM Subject: Re: On the =?iso-8859-1?Q?=E 2 =80=9Ccrystallogr ap hic_good_practic es= E2=80=9D?= Leonid, good point

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