Re: fractional occupancy and composition within GSAS

2009-12-02 Thread Brian Toby
The short answer here is read the code that does this, which I have not done anytime recently. What I recall is the unit cell composition is simply the sum of site multiplicities times the fractional occupancy for each site grouped by atom type. The way I come up with z is something of a

Re:

2005-07-02 Thread Brian Toby
Dear Milinda, I have added you to my mailing list for information about EXPGUI (the GSAS user interface). When I have time, I make updates and send out mail to that list. If you have questions, you likely want to join the Rietveld mail server, where people have discussions on the technique and

Re: DBWS vs other refinement programs

2005-07-01 Thread Brian Toby
http://danse.cacr.caltech.edu/polls/results.php?sid=22 Of course, the number of people using Rietveld software is more than 269 (number of answers in the survey) The number of respondents to the survey is ~150, but Rietveld users (at least the ones who took the time to participate) on average

Re: mismatch between ICSD cif file and GSAS

2005-05-17 Thread Brian Toby
On May 17, 2005, at 12:31 AM, Donald Wang wrote: x-tad-biggerAfter 1/8 offset, it appears that the pattern from live plot is a good match to ICSD-generated pattern, which basically solved my problem.  I am very happy and grateful./x-tad-bigger x-tad-bigger /x-tad-bigger x-tad-biggerThere is still

Re: Laboratory Information Management Systems (LIMS)

2005-04-25 Thread Brian Toby
At 14:43 22/04/2005, Angus P. Wilkinson [EMAIL PROTECTED] wrote: Do none of the user facilities have a data management system in place for their instruments? Well yes Angus :-) For the past 30+ years ILL has stored all instrument data as simple ASCII files with a data format described in the

Re: Change format

2005-03-30 Thread Brian Toby
your data are free format with intensities as a real variable. Using excel or any equivalent you can convert in integer intensities (e.g. multiplying by ten to avoid errors with low values) which is the usual data input (counts). Step 2 is then to convert the free 2th-I (real-integer) file into

Re: RIET:CLAY: IUCr 2005: Crystallographic Software Fayre at IUCr Florence, Italy 2005 Congress

2005-03-14 Thread Brian Toby
I should think about doing something -- what makes most sense CMPR, EXPGUI, GSAS2CIF or pdCIFplot? I tend to think CIF is the most important with the Acta's now asking for powder CIFs. What to you think? BTW, at least for me, invited talks matter and other talks don't. As part of my goal of

Re: Rigid body constraints on perovskite structured materials

2004-11-12 Thread Brian Toby
I will wade in on this topic quickly. Rigid body constraints can be used for two linked bodies pretty easily -- what one does is define the origin of each body as an atom that shared between each body (note that this atom needs to be present in the atom list twice, so adjust occupancies to

Re: Instument parameter file

2004-03-18 Thread Brian Toby
Theoretically U,V,W should not be refined at all as they describe instrumental broadening This is true only when there is no Gaussian strain present. Brian

Re: Sequential refinement with GSAS

2001-08-31 Thread Brian Toby
I need to make Rietveld analysis with big amount of data files and I would like to ask you if you know is it possible to make GSAS refinement for many files at the same time or is there some procedure to do analysis automatically for some consequence of files. I agree that this is a valuable