Re: GSAS with energy dispersive data

L. Cranswick ( L.M.D.Cranswick@dl.ac.uk )
Mon, 30 Mar 1998 00:42:33 +0100 (BST)

On a more general note - would it be possible to get
information on software that works
with Energy Dispersive data - and what
it does - so that a summary can be put together in the same
way one on Incommensurate/Modulated Structure Software was?
(http://www.dl.ac.uk/CCP/CCP14/solution/incomm.htm)

Energy Dispersive is quite mysterious when it comes to
software - functionality appears in some programs -
then just as fast - disappears????

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In the case of peak/background fitting:If you refer to the XFIT peak fitting tutorial at: http://www.dl.ac.uk/CCP/CCP14/tutorial/xfit-95/xfit.htm

XFIT can definitely fit Energy Dispersive peaks anddata in a time effective manner. If youare doing unit-cell refinement or kinetics studies, etc.Over other software tried - XFIT is at least an order ofmagnitude faster and more efficient. http://www.dl.ac.uk/CCP/CCP14/tutorial/xfit-95/xfit.htm#energyd and http://www.dl.ac.uk/CCP/CCP14/tutorial/xfit-95/fsinxrd.htmLess contrived examples for the tutorial are planned.

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Though this is not to say that if custom data-processingsoftware was written using modern human and genetic algorithmsfor the "hack analysis" (peak fitting, unit-cellrefinement, areas, etc) of thousands of Energy Dispersive spectra - that if could not be done at least a few orders of magnitude faster than XFIT(?). (I think this readscorrectly?)

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Hope to be uploading an automatic Energy Dispersive Calibrationdetermination program and a data calibration/conversion program in the next few days to weeks - as soon as the program authors think they are acceptable for publicuse.

Lachlan.

PS: If people would like to create summaries or providegraphics to support their discussions on the mailing list - CCP14 web-space is available for inserting this information if you lack any stable web-space yourself.

> It may be FAQ and sorry for this mail. I'm considering to> use GSAS to obtain unit-cell parameters (and more) from energy> dispersive (ED) pattern of low symmetry material. Recently I read> a paper which mentioned modified GSAS for ED data (Zhao et al.,> 1997, Geophysical Research Letters, 24, 5-8). I checked GSAS> homepage and document files. Although GSASNEWS file mentioned that> ED data can be used, I can't find any instruction. > Is there special version of GSAS for ED data? Or can I use> normal(?) GSAS for them? If so, is there any available instruction? > In addition, I would appreciate if I can get valuable advice on > using GSAS for ED data.> DAN> > -----------------------------------------------------------------> Sang-Heon (Dan) Shim > Department of Geosciences office:(609)258-3261> Princeton University home:(609)258-8977 > Princeton, NJ 08544-1003 fax:(609)258-1274> http://www.princeton.edu/~sangshim sangshim@geo.princeton.edu > ----------------------------------------------------------------->

-- Lachlan M. D. CranswickCollaborative Computational Project No 14 (CCP14)    for Single Crystal and Powder DiffractionDaresbury Laboratory, Warrington, WA4 4AD U.KTel: +44-1925-603703  Fax: +44-1925-603173  E-mail: l.cranswick@dl.ac.uk   Ext: 3703  Room C14CCP14 Webpage (Under heavy reconstruction):   http://www.dl.ac.uk/CCP/CCP14/

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