RE: Intrumental broadening of 2D detector

Hi Wing, I purchased LaB6 from http://www.thegemdugout.com/ for a fraction of price NIST charges and the same quality. Peter Zavalij X-ray Crystallographic Center University of Maryland College Park, MD 20742 Phone: 301-405-1861 From: Julian Tolchard [mailto:tolch

RE: the error bars of lattice parameters using GSAS

Jin, Make sure you refine a,b,c in the last refinement cycle. If you fix the at some points the error "bars" are gone. Peter Zavalij X-ray Crystallographic Center University of Maryland College Park, MD 20742 Phone: 301-405-1861 From: Peng, Jin [mailto:jpe...@

Re: notes on rietveld method

Thanks Armel, I did told author of this request about my book. I didn't reply to whole list - it does not seem right to advertise (too much) your own work. This can even have negative impact. Peter Dr. Peter Y. Zavalij Director, X-ray Crystallographic Laboratory Department of Chemistry & Bioch

notes on rietveld method

Dear Vikrant, I don’t think you could write Rietveld program using only online notes. It may take some learning to get into the methods (in depth learning if you want to write program). Dr. Peter Y. Zavalij  Director, X-ray Crystallographic Laboratory Department of Chemistry & Biochemis

Re: mismatch between ICSD cif file and GSAS

the refinement. Otherwise we run into another problem when changes in atomic coordinates do not move atom to different site. Peter Zavalij From: Brian Toby [mailto:[EMAIL PROTECTED] Sent: Tuesday, May 17, 2005 11:20 AM To: rietveld_l@ill.fr Subject: Re: mismatch between ICSD cif

Re: introduction + question

a on a CD-ROM: Fundamentals of Powder Diffraction and Structural Characterization of Materials by Vitalij Pecharsky and Peter Zavalij, Springer, 2003, ISBN: 1-4020-7365-8. http://www.springeronline.com/sgw/cda/frontpage/0,11855,4-40109-22-39525831- 0,00.html Though due to its price - it might be

introduction + question

cupancies can be exposed - maybe. Thus to end I would recommend looking for trends rather than just looking at a single sample and believing the refinement results. Alan -Original Message----- From: Peter Zavalij [mailto:[EMAIL PROTECTED] Sent: Thursday, May 05, 2005 8:16 PM To: rietveld

introduction + question

the limit is reached there's a phase transition. It may very well be the case that your system has no vacancies but I would not assume it at first. alan -Original Message----- From: Peter Zavalij [mailto:[EMAIL PROTECTED] Sent: Thursday, May 05, 2005 6:44 PM To: rietveld_l@ill.fr We

introduction + question

http://icpet-itpce.nrc-cnrc.gc.ca -Original Message- From: Peter Zavalij [mailto:[EMAIL PROTECTED] Sent: May 5, 2005 11:36 AM To: rietveld_l@ill.fr Alexander: I just finished combined X+N refinement of similar battery materials but w/o V with Li in 2a site and Mn, Co and Ni in 2b (or vis

introduction + question

Alexander: I just finished combined X+N refinement of similar battery materials but w/o V with Li in 2a site and Mn, Co and Ni in 2b (or vise versa). Chemical composition was well known; The problem we were looking for was migration/exchange of transition metal from 2b to 2a. That's not so simple p

Stefan Melzer/IJmuiden/CorusGroup is out of the office.

Wow! 5 month of vacations, no wonder it's confidential. Peter Y. Zavalij Director, X-ray Crystallographic Laboratory Department of Chemistry & Biochemistry 091 Chemistry Building University of Maryland College Park, MD 20742-4454 Phone: (301)405-1861 Fax: (301)314-9121 E-mail: [EMAIL PROTECTE

absortion correction

There are several function in GSAS for absorption correction. For Bragg-Brentano geometry the best is Suorti (#3). This correction (coeff.1 & Coeff.2 in range of .2-.5) is designed primarily for porosity correction but is does good job with absorption correction and any other correction th

RE: Mathematics - Fundamentals of Powder Diffraction and

Yes, it priced very high by publisher. However there is option to order 6 or more books through university bookstore and get around 30% discount. I also heard that some bookstores were able to order for as low as $96 per book. Peter Zavalij -Original Message- From: Lachlan Cranswick

RE: Mathematics

Or newer book Fundamentals of Powder Diffraction and Structural Characterization of Materialsat http://www.springeronline.com/sgw/cda/frontpage/0,0,4-0-22-33289750-0,0.html?referer=www.springeronline.com/isbn/1-4020-7365-8   http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6X1J-4CKJV

space group + symmetry positions

2a & 2b yield the same structure that has c'=c/2 so this is not case. 2c & 2d yield again the same structure which is hexagonal close-packed - Mg structure type. Check cell dimensions against know structure types. Peter Zavalij University Crystallographer Institute for Materials

space group + symmetry positions

Do you know what structure type it is? If yes just take the same atomic position for you compound as for the known one. If not you have to find it. Anyway... be careful with the space group symbol - It should be "P 63/m m c" not "P 6 3 /m m c". NO SPACE between 6 & 3. Pe

back loading

Actually any Extra-hold or Maximum-hold hair spray works fine. I use it not necessarily on the backload sample but on any spinning sample even so the sample is horizontal. It's a bit tricky to put but it you keep at least 25-20 cm distance and do it slowly it works fine. Peter -Original Mess

PDF-4

I believe the PDF-4 database is based on the Microsoft access but I am not sure the format is public. Peter Zavalij University Crystallographer Institute for Materials Research and Chemistry Department Binghamton University, SUNY, Vestal Pkwy, East Binghamton, NY 13902-6000, USA Tel: (607)777

Returned mail: see transcript for details

cure for this. Peter Zavalij University Crystallographer Institute for Materials Research and Chemistry Department Binghamton University, SUNY, Vestal Pkwy, East Binghamton, NY 13902-6000, USA Tel: (607)777-4298Fax: (607)777-4623 E-mail:[EMAIL PROTECTED] http://materials.binghamton.edu/za

RE: Generator for Scintag

Hi everyone, Sorry for asking again but I am not sure I send this message first time. I am looking for an old/used generator for Scintag XDS2000 diffractometer. New one is too expensive as for old machine. Any suggestions/contacts are welcome. Thanks in advance, Peter Zavalij University

RE: Form factors for Ni4+ and Co4+

Simply use just Dr. Peter Y. Zavalij University CrystallographerInstitute for Materials Researchand Chemistry DepartmentBinghamton University, SUNY, Vestal Pkwy, EastBinghamton, NY 13902-6000, USATel: (607)777-4298    Fax: (607)777-4623E-mail:[EMAIL PROTECTED]http://materials.binghamton.ed

Generator for Scintag

Hi everyone, I am looking for an old/used generator for Scintag XDS2000 diffractometer. New one is too expensive as for old machine. Any suggestions/contacts are welcome. Thanks in advance, Peter Zavalij University Crystallographer Institute for Materials Research and Chemistry Department

Problem: GSAS

ifically for each case... Peter Zavalij University CrystallographerInstitute for Materials Researchand Chemistry DepartmentBinghamton University, SUNY, Vestal Pkwy, EastBinghamton, NY 13902-6000, USATel: (607)777-4298    Fax: (607)777-4623E-mail:[EMAIL PROTECTED]http://materials.

Question about dealing with size and Strain in Rietveld

Reference to PSF #4 by P. Stephens is J. Appl. Cryst. (1999). 32, 281-289. Peter Y. Zavalij University Crystallographer Institute for Materials Research and Chemistry Department Binghamton University, SUNY, Vestal Pkwy, East Binghamton, NY 13902-6000, USA Tel: (607)777-4298Fax: (607)777-4623

Question about dealing with size and Strain in Rietveld

The approach you use describes anisotropy of the peak broadening in ellipsoidal approximation and it is not strange that fit is improved. The question is how adequate the model is. You may also try PSF #4. There was a lot of discussion recently on this list about the anisotropic broadening and pe

Powder Diffraction SIG at ACA annual meeting, July 17-22, Chicago 2005

topics and workshops, or anything else you may wish to bring to our attention. Sincerely yours, Peter Zavalij __ Contact information: Abraham Clearfield, Chair 04 Dept. of Chemistry Texas A & M Univ. PO Box 30012 College Station TX 77843-3255 Tel: 979 845

Fixing parameters in GSAS

Brian is right there are no F (holding atomic parameters in EXPGUI). I messed F up with V. However I found no problem to remove them using D. Simply type "D #" where # is number of holding parameter. To check list of holding parameters (better before and after D) type "L&q

Fixing parameters in GSAS

The easiest way is to use EXPGUI graphic user interface by Brian Toby. Peter Zavalij -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday, April 22, 2004 5:05 AM To: [EMAIL PROTECTED] Dear all Rietvalders, Can anyone know how to delete the holding

Fullprof: Le Bail fit for incommensurate structures?

Maxim, I think the best way to do incommensurate structure is Jana. Peter -Original Message- From: Maxim V. Lobanov [mailto:[EMAIL PROTECTED] Sent: Monday, April 12, 2004 4:49 PM To: [EMAIL PROTECTED] Dear collegaues, I would be grateful if somebody could tell me if it is possible to do

Re: GSAS informations

>From my experience both functions #3 and #4 work fine when broadening anisotropy is >not significant. I found #4 more works better when anisotropy is large (up to 2 times); in this case improvement is substantial Peter Zavalij -Original Message- From: Maxim V. Lobanov [mailto:

Re: Defining the origin of P2/n

conclusions correct space group symbol with properly placed spaces has to be used. Peter Zavalij -Original Message- From: Allen Larson [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 31, 2004 11:58 AM To: [EMAIL PROTECTED] Peter Zavalij wrote: > > Bob, > Thank you for the clar

Defining the origin of P2/n

Bob, Thank you for the clarification. I never had doubts that GSAS handles fixed origin issue properly but also never understand how it is done. This way has one big advantage over user fixed origin -- it yields standard uncertainties for all atoms and therefore for all distances, etc. Peter

RE:

.   Peter Zavalij    - Original Message - From: Peter Zavalij To: [EMAIL PROTECTED] Sent: Friday, March 26, 2004 12:57 PM Subject: RE: This is quite comprehensive question(s) and even not so comprehensive answer could not be placed in one e-mail

RE:

; P.Y.Zavalij. Kluwer Academic Publishers, Spring 2003. (www.amazon.com, www.wkap.nl)   Peter Zavalij -Original Message-From: ling yang [mailto:[EMAIL PROTECTED]Sent: Friday, March 26, 2004 11:58 AMTo: [EMAIL PROTECTED]Subject: Dear all,   I have some questions concerning

Re: Instument parameter file

tal files have to be created for each diffractometer configuration used (e.g. different slits). Peter Zavalij Dr. Peter Y. Zavalij University Crystallographer Institute for Materials Research and Chemistry Department Binghamton University, SUNY, Vestal Pkwy, East Binghamton, NY 13902-6000, US

RE: Rietveld question - EXPGUI

The best way is to check generated symmetry operations with International tables for crystallography or on-line using, for example, Bilbao server: http://www.cryst.ehu.es/cryst/get_gen.html which has all conventional and non-conventional settings and much more. Peter Dr. Peter Y. Zavalij Un

Rietveld question - EXPGUI

Dear Nichole,   Space between 4 and 2 does not make any sense and results in P 4/m m m symmetry.   BUT for sure spaces surrounding "/" should be removed and space groups symbol should as following: "P 42/n m c".   Note that S is not part of the space group symbol and is probably ignored b