Thanks Chris. Regards.
2014-03-18 11:54 GMT-03:00 Chris Patridge <patri...@buffalo.edu>: > Hello, > > I think it is valid. The model for v2o5 is tough to fit well at low R > because the apical oxygen bond is so short that there is some significant > overlap between the background and signal near 1 angstrom. > > Chris > > ******************************************** > Dr. Christopher Patridge > Assistant Professor of Chemistry > Math and Natural Science Dept > BFAC 009 > D'Youville College > 320 Porter Ave., Buffalo, NY 14150 > 716-829-8096 > > Sent from my iPhone > > > On Mar 18, 2014, at 10:31 AM, Douglas Langie da Silva < > douglaslan...@gmail.com> wrote: > > > > Dear all, > > > > I am working with EXAFS data of V2O5 xerogel. In this form, the V2O5 > present a monoclinic structure formed by bi-layers of VO5 pyramids > intercalated with water molecules. Fig 1 attached presents a view of the > V2O5 xerogel structure. There are two Vanadium atoms per unit cell, each > one surrounded by oxygen atoms at distinct distances, characterizing two > inequivalent sites. > > My question is how to fit the data in dartemis considering the two > inequivalent positions? > > > > My first approach was run Feff two times. Then I get two theoretical > models, one for V1 atoms and the other for the V2 atoms. Each of Feff runs > are present attached as model V1 and model V2. After that I transfer the > paths of the first shell of each model to dartesmis data windows (fig 2) > and proceed with the fit. We pay attention in the site fraction of each > vanadium atom in order to setup the S02 parameter for each model. Without > attempting at this point with the numbers, the final results are present in > Fig. 3 e 4. Fig 4 presents the log file and the results for the each patch. > > > > My question is: this procedure is valid? > > > > Since now thak you. > > > > -- > > Douglas Langie da Silva > > Instituto de Física e Matemática > > Departamento de Física > > Universidade Federal de Pelotas > > Campus Universiário s/n > > CP 354 > > Pelotas/RS > > CEP 96010-900 > > 55 53 32757477 > > 55 53 32757345 > > > > Douglas Langie da Silva > > Physics Department > > Federal University of Pelotas > > POBox 354 > > Pelotas/RS > > ZCode 96010-900 > > 55 53 32757477 > > 55 53 32757345 > > <Rav 1.jpg> > > <Model v1.jpg> > > <Model v2.jpg> > > <Fig 3.jpg> > > <Fig 4.jpg> > > _______________________________________________ > > Ifeffit mailing list > > Ifeffit@millenia.cars.aps.anl.gov > > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > > _______________________________________________ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > -- Douglas Langie da Silva Instituto de Física e Matemática Departamento de Física Universidade Federal de Pelotas Campus Universiário s/n CP 354 Pelotas/RS CEP 96010-900 55 53 32757477 55 53 32757345 Douglas Langie da Silva Physics Department Federal University of Pelotas POBox 354 Pelotas/RS ZCode 96010-900 55 53 32757477 55 53 32757345
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