Re: scattering factor for O2- ?

Peter Y. Zavalij, PHD Director - X-ray Crystallographic Center University of Maryland, College Park, MD 20742 On Tue, Feb 21, 2023 at 1:11 PM Toby, Brian H. wrote: > I am going to make the comment that (A) neutral atom form fact

Re: understanding peak width broadening during LiOH growth

Now Topas has anisotropy built in the GUI version too. No script is needed. Peter Peter Y. Zavalij, PHD Director - X-ray Crystallographic Center University of Maryland, College Park, MD 20742 On Tue, Aug 2, 2022 at 9:16 AM

Re: Rietveld website cancelled ?

solution). Peter Peter Y. Zavalij Director - X-ray Crystallographic Center University of Maryland, College Park, MD 20742 On Wed, Aug 29, 2018 at 12:38 PM David Elbert wrote: > Absolutely important that people underst

Re: Sample damaging during XRD

>From my experience some transition metal oxides, like MoO3, WO3 etc, turns slowly blue under X-tay, assumedly due to metal reduction. Peter Zavalij On May 22, 2017 10:00 AM, "Payzant, E. Andrew" wrote: > You can run into “interesting” behavior with metastable phases. I once

Re: How much COD and PDF database gives the complete known structures?

published data not included in any database. Peter Y. Zavalij Director - X-ray Crystallographic Center University of Maryland, College Park, M ​aryland On Tue, Jan 10, 2017 at 10:12 AM, Shay Tirosh <stiro...@gmail.com>

Re: CrySize error in TOPAS

as it is basically beyond the limt of the methods. Peter Dr. Peter Y. Zavalij Director - X-ray Crystallographic Center University of Maryland, College Park, MD 20832 On Wed, Jul 27, 2016 at 1:07 PM, "Łukasz Kruszewski"

RE: a request to Russia

FYI: Kristallografiya was translated into English as Soviet Physics Crystallography and can be found in many western libraries. Although I am not sure what year they started translation. Could be after 1966. Peter Z. __ Peter Zavalij Director, X-ray

RE: structure solution terminology

How about "reciprocal methods" as opposite to "direct methods" which work in reciprocal space? Peter __ Peter Zavalij Director, X-ray Crystallographic Center University of Maryland, College Park, MD 20742 http:/www.chem.umd.edu/crystallography

RE: Instrumental resolution function

, September 15, 2013 10:05 PM To: Peter Y. Zavalij; mariomac...@tux.uis.edu.co; rietveld_l@ill.fr Subject: RE: Instrumental resolution function Hi Peter, Mario I happen to have a Ni filter, Cu, LaB6 pattern that has a very similar look to the one sent by Mario. Probably best to look at the 21.35

RE: Instrumental resolution function

...@oit.edu] Sent: Monday, September 16, 2013 12:08 PM To: Peter Y. Zavalij; Alan Coelho; mariomac...@tux.uis.edu.co; rietveld_l@ill.fr Subject: RE: Instrumental resolution function Alan, Peter, Would you mind briefly elaborating on the procedure used to fit tube tails? I personally have only used GSAS

RE: Instrumental resolution function

Hi Mario, The shoulder you observe is what's left from white after it is cut off by beta-filer. You could check the absorption edge of Ni and it is right at the shoulder you observe. Peter __ Peter Zavalij X-ray Crystallographic Center University of Maryland

RE: BVS at non-ambient conditions?

Maxim, Generally bond length are not temperature depended (correct me if I am wrong). So you don't have to do anything if non-ambient means different temperature but I am not sure about pressure etc. Peter __ Peter Zavalij X-ray Crystallographic Center University

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

At the end it is all wrong as we don’t refine individual electrons but restrained groups that are called “atoms” which are extrapolated with some average function calculated for free, unbounded atom. Peter Zavalij From: rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] On Behalf Of

conversion

What software is used to convert neutron data in *.bt1 format to any commonly used format, e.g. GSAS? Thanks Peter Zavalij  X-ray Crystallographic Center University of Maryland College Park, MD Office: (301)405-1861 Lab: (301)405-3230 Fax: (301)314-9121

RE: References on quantitative phase analysis using GSAS

Another book on powder diffraction and rietveld refinement partially based on GSAS with real examples to follow up the text also describes variety of quantitative analyses: http://www2.chem.umd.edu/facility/xray/FPDSCM2.htm Dr. Peter Y. Zavalij  Director,  X-ray Crystallographic Center Department

RE: Negative Equivalent Isotrpic Calculated Values Problem..

One of the reasons could be preferred orientation. If this is the case, one could derive orientation axis from the ellipsoids. Peter Zavalij  X-ray Crystallographic Center University of Maryland College Park, MD Office: (301)405-1861 Lab: (301)405-3230 Fax: (301)314-9121 -Original

RE: cRs

: Beekman, Matthew [mailto:mbeek...@cas.usf.edu] Sent: Saturday, March 07, 2009 7:20 PM To: Peter Y. Zavalij; rietveld_l@ill.fr Subject: RE: cRs Hello all, A quick question regarding the background subtracted R values: In the .LST file, GSAS gives two sets of values for wRp and Rp: Fitted

RE: background subtraction R values

Are these flavored comments appropriate for scientific discussion? Peter Zavalij  -Original Message- From: Smirnova Olga [mailto:olga.smirn...@hw7.ecs.kyoto-u.ac.jp] Sent: Sunday, March 08, 2009 5:58 AM To: Brian H. Toby; rietveld_l@ill.fr Subject: Re: background subtraction R values

RE: cRs

There are others important criteria of refinement quality implemented in many software but rarely analyzed or published. These are Rp' and Rwp' calculated with background subtracted from both observed and calculated data. They are especially important when dealing with high background cases, e.g.

RE: error in peak positions that is linear in theta

Kurt, It looks like incorrect step size (difference between actual step size and one that is written in the file) or incorrect distance to the detector. The later may incorrect step size if detector is PSD. I have similar situation with much smaller difference in peak position but the shift

text/reference book Fundamentals of Powder Diffraction and Structural Characterization of Materials. 2nd Edition

FYI: 2nd edition our powder diffraction book has been just released (paperback): Fundamentals of Powder Diffraction and Structural Characterization of Materials. 2nd Edition Vitalij K. Pecharsky Peter Y. Zavalij, Springer 2009. See Springer webpage www.springer.com/978-0-387-09578-3 for the book

RE: Preferred orientation?

Kurt, An old way used for alloys is: grease the surface of the sample holder (preferably backgroundless) with some sticky stuff and sieve the powder onto it. The particles will fall down and stuck at random orientations, unless they are large plates or needles. Peter Zavalij Director, X-ray

Home page location

What is current home page of the Rietveld users' mailing list? Links that I have are either not valid or mirrors. Many thanks, Peter Zavalij Director, X-ray Crystallographic Center Department of Chemistry and Biochemistry 091 Chemistry Building University of Maryland College Park, MD 20742-4454

RIETICA question

Does anyone know how to tell Rietica to account for background (from sample holder, film, etc.) stored in separate file? Rietica can do it but there is no much about how to set it up in the manual. Thanks, Peter Zavalij

RE: Neutron or X-ray?

Davide, Could you perform Rietveld refinement using combined neutron and x-ray data? This would increase accuracy and the question what is better would disappear. Basically all you need is both data done at the same temperature. Also look at neutron and x-ray scattering factors. The neutron

RE: GSAS total beginner questions

Try out Pow_DLL: http://users.uoi.gr/nkourkou/powdll.htm It converts practically anything into anything. Dr. Peter Y. Zavalij Director, X-ray Crystallographic Center Department of Chemistry and Biochemistry 091 Chemistry Building University of Maryland College Park, MD 20742-4454 Phone: (301

RE: Crystallography/MS Word Question: 3 bar

choose Insert symbol. You could create shortcut to this bar and insert it before 1 P¯1but also you need to select this bar and make font condensed by about 6 pt. The crystallographic 1bar looks like this: 1 . Peter Dr. Peter Y. Zavalij Director, X-ray Crystallographic Center Department

RE: Amorphous content

it. Pam *From:* Peter Y. Zavalij [mailto:[EMAIL PROTECTED] *Sent:* November 15, 2007 9:07 PM *To:* rietveld_l@ill.fr *Subject:* Amorphous content Hi, I am trying to determine amorphous content using Rietveld refinement and internal standard. However resulting content of amorphous phase

RE: Sources of standard reference materials

Ross, The link to The Gem Dugout X-ray Diffraction Products is http://www.thegemdugout.com/products.html. The provide several reference specimens for affordable price, e.g. LaB6 - $10/g. And other diffraction products. Peter Dr. Peter Y. Zavalij Director, X-ray Crystallographic Laboratory

Amorphous content

Hi, I am trying to determine amorphous content using Rietveld refinement and internal standard. However resulting content of amorphous phase is really unrealistic. Moreover testing the method using standards with known amorphous content does not clarify the situation. For example ZnO (NIST, 95%

RE: Hello

Tom, We just replaced Gobel mirror that had the same problem/symptoms. Now we are back to normal intensity. Dr. Peter Y. Zavalij Director, X-ray Crystallographic Laboratory Department of Chemistry Biochemistry 091 Chemistry Building University of Maryland College Park, MD 20742-4454 Phone

powplot config of figures for publication

. Von Dreele IPNS Division Argonne National Laboratory Argonne, IL 60439-4814 -Original Message- From: Peter Y. Zavalij [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 18, 2006 1:52 PM To: rietveld_l@ill.fr The best (not the fastest) way is to import observed and calculated plots from CIF

powplot config of figures for publication

The best (not the fastest) way is to import observed and calculated plots from CIF file into Excel spreadsheet and then do to the plot whatever is desired. Reflections can be shown as error but using imported 2theta. I have template that does scaling, etc. automatically (to some extend). Peter

RE: Site occupation factor in atoms

You could do it approximately by introducing atom type with proper seq. number (no. of electrons). For example if you have Fe (26 electrons) with 50% occupancy you could use Al (13 electrons). It is good enough for powder pattern calculation. Peter Zavalij -Original Message- From: Ana

RE: Negative displacement params in neutron refinement

Very probably you should refine preferred orientation 0,0,1. If it take place you'll see improved adp's. Dr. Peter Y. Zavalij University Crystallographer Materials Research Center, SUNY at Binghamton Tel: (607)777-4298Fax: (607)777-4623 E-mail:[EMAIL PROTECTED] http

RE: new GSAS

Windows 2000 does allow to associate many program to the same extension using "Advance" button. Dr. Peter Y. Zavalij University Crystallographer Materials Research Center, SUNY at Binghamton Tel: (607)777-4298Fax: (607)777-4623 E-mail:[EMAIL PROTECTED] http://materials.bing

RE: Atoms 5.0 and Win2000

This is strange but Atoms 5 works fine under w2k on my PC. -Original Message- From: jools [mailto:[EMAIL PROTECTED]] Sent: Saturday, December 02, 2000 5:24 AM To: [EMAIL PROTECTED] Subject: Atoms 5.0 and Win2000 Does anyone have any experience of getting Atoms v5.0 to run under win2k

RE: TiB2 crystal structure

To my recollection it is AlB2 structure type: sp.gr. P6/mmm, a=3 A, c=3.2 A Al in 0,0,0 B in 1/3,2/3,1/2 Peter Zavalij -Original Message- From: Anthony Manerbino [mailto:[EMAIL PROTECTED]] Sent: Thursday, November 23, 2000 11:54 AM To: '[EMAIL PROTECTED]' Subject: TiB2 crystal

RE: RETRIEVE

Same happens on Windows 2000. Mouse does not work even with DOS mouse installed. So I use no mouse. It is still possible... -Original Message- From: Davide Levy [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 21, 2000 4:30 AM To: [EMAIL PROTECTED] Subject: RETRIEVE Is there anybody

RE: RETRIEVE

You may use comand line (F4), for example: V and O and Mn and ELC=3 will give you all compounds containing only V, Mn and O. See printed manual for other posibilirties. -Original Message- From: Habib Boughzala [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 21, 2000 12:05 PM To:

Re: Peak shift in Debye-Scherrer-geometry

The equation (2) is nothing else but specimen shift in the Bragg-Brentano geometry. I have a question concerning the systematic line shifts due to sample off-centering in the Debye-Scherrer-geometry. The shift D2Theta due to an eccentricity e in the incident beam direction is always given as