- Ifeffit - millenia.cars.aps.anl.gov

Re: [Ifeffit] Ifeffit Digest, Vol 82, Issue 3
by Michel Jaouen 07 Dec '09

07 Dec '09

Hi Eugenio, >I want to estimate the influence of every shell in XANES simulations like >Bruce Ravel shown in the publication: "A practical introduction to multiple >scattering theory" >I always done simulations until the system is converged, so now I have a >doubt, should I increse the SCF until convergence and add new shells in FMS >to repeat this kind of results? Just run feff with CONTROL 0 0 1 1 1 1 (you didn't need to recalculate the pot and phase modules) and change the FMS rfms. Best regards, Michel -- __________________________________________ Michel Jaouen Universite de Poitiers - UFR Sciences - SP2MI Laboratoire de Physique des Matériaux (PhyMat) UMR 6630-CNRS Boulevard Pierre et Marie Curie - Teleport 2 BP 30179 86962 Futuroscope - Chasseneuil Cedex France Tel : (33) 5 49 49 67 37 Fax : (33) 5 49 49 66 92 e-mail : Michel.Jaouen(a)univ-poitiers.fr __________________________________________

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Double crystal monochromator
by sankaran anantharaman 04 Dec '09

04 Dec '09

Hi everyone, Could anyone help me with this. Why is that the Darwin reflectitivity curve plotted versus rotation angle (in text books for example) and rocking curve plotted against rotation angle (observed in the oscilloscope at XAS beamlines for example) look different? I understand that the double crystal rocking curve (photon counts in Ionization chamber1 as a function of Bragg angle) is obtained by rotating the second crystal and recording the photon count. Is it right? Regards, Sankaran Anantharaman

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Shells in XANES
by Eugenio Otal 03 Dec '09

03 Dec '09

Hi, I want to estimate the influence of every shell in XANES simulations like Bruce Ravel shown in the publication: "A practical introduction to multiple scattering theory" I always done simulations until the system is converged, so now I have a doubt, should I increse the SCF until convergence and add new shells in FMS to repeat this kind of results? Thanks in advance, euG

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Mackale's Table for backscattering amplitude
by Neetu parsai 03 Dec '09

03 Dec '09

Hello Can some one send me Mackale's table in which back scattering amplitude and Phase shift values of most of the elements are given. Otherwise can tell me how can I order that table. Thanks with best regards Mrs.Neetu Parsai Head Department of Engg.Physics Sanghvi Innovative Academy Indore. Residence: 130 Hemu colony, New G.D.C.Road, Indore-452015(M.P.) India.

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Open position at HASYLAB
by Welter, Edmund 01 Dec '09

01 Dec '09

Dear XAFS users, if you are interested or know someone who might be interested in a postdoc position in the field of spectroscopy with X-rays, please have a look at our recent job advertisement: http://www.desy.de/v2/docs/1257511440-e.pdf Regards, Edmund Welter

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Re: [Ifeffit] Ifeffit Digest, Vol 81, Issue 25
by Jasquelin Pena 30 Nov '09

30 Nov '09

Scott, .cif files for many minerals can be downloaded from the AMCSD: http://rruff.geo.arizona.edu/AMS/amcsd.php Jasquelin On Mon, 30 Nov 2009, ifeffit-request(a)millenia.cars.aps.anl.gov wrote: > Send Ifeffit mailing list submissions to > ifeffit(a)millenia.cars.aps.anl.gov > > To subscribe or unsubscribe via the World Wide Web, visit > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > or, via email, send a message with subject or body 'help' to > ifeffit-request(a)millenia.cars.aps.anl.gov > > You can reach the person managing the list at > ifeffit-owner(a)millenia.cars.aps.anl.gov > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Ifeffit digest..." > > > Today's Topics: > > 1. Re: Request a .cif file for alpha & beta Nickel hydroxide > (Scott Wicker (Student)) > 2. Re: Request a .cif file for alpha & beta Nickel hydroxide > (Bruce Ravel) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 29 Nov 2009 12:06:19 -0600 > From: "Scott Wicker (Student)" <scott_wicker_00(a)subr.edu> > To: "XAFS Analysis using Ifeffit" <ifeffit(a)millenia.cars.aps.anl.gov> > Subject: Re: [Ifeffit] Request a .cif file for alpha & beta Nickel > hydroxide > Message-ID: > <301F55994159DB4682AA882A772707E1013EF192(a)primary14.subr.edu> > Content-Type: text/plain; charset="iso-8859-1" > > I would like to request a .cif file for the alpha & beta Nickel hydroxide. If someone also have .cif files for Cobalt hydroxide this will be greatly appreciated. Is there a single crystal data base for .cif files? > > thanks, > > Scott A. Wicker Sr. > Ph.d Graduate Student > Environmental Toxicology > Southern University A & M > Baton Rouge, LA 70813 > School: scott_wicker_00(a)cxs.subr.edu > Home: swicker(a)cox.net > > > > -----Original Message----- > From: ifeffit-bounces(a)millenia.cars.aps.anl.gov on behalf of Frenkel, Anatoly > Sent: Fri 11/27/2009 1:12 PM > To: jswashin(a)ncsu.edu; XAFS Analysis using Ifeffit > Subject: RE: [Ifeffit] Bond length determination EXAFS vs XRD > > XRD measures interplanar spacing, and XAFS - interatomic distances, and they are not the same if disorder is present. Look for articles by Boyce and Mikkelsen, Jr., in Phys Rev B in 1980's who were the first discussing these concepts in GaAs-InAs semiconductors and also KBr-RbBr ionic salts. > They showed that the average structure ascertained by diffraction differs from the local structure measured by EXAFS. > Modern day high energy XRD/PDF measures interatomic distances more accurately than Bragg peak analysis can do but how accurately it agrees with EXAFS is still subject of debates. > Anatoly > > > _____ > > From: ifeffit-bounces(a)millenia.cars.aps.anl.gov on behalf of Joseph Washington > Sent: Fri 11/27/2009 2:08 PM > To: XAFS Analysis using Ifeffit > Subject: [Ifeffit] Bond length determination EXAFS vs XRD > > > > Happy Thanksgiving All! > > Can someone, send me some references which explains some of the reasons > why the bond lengths fitted in EXAFS would be different from that fitted > in XRD (assuming that we implemented the crystal model predicted by XRD > correctly in Artemis)? > > I would really appreciate this! > > Sincerely > -- > Joseph Washington > Research Assistant > Department of Physics > North Carolina State University > 431 Riddick Hall > Raleigh, NC 27695-8202 > email: jswashin(a)ncsu.edu > _______________________________________________ > Ifeffit mailing list > Ifeffit(a)millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > > > >

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Request a .cif file for alpha & beta Nickel hydroxide
by Eugenio Otal 30 Nov '09

30 Nov '09

Try with this database: http://www.icsd.iqfr.csic.es/ Regards, euG

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Bond length determination EXAFS vs XRD
by Joseph Washington 30 Nov '09

30 Nov '09

Happy Thanksgiving All! Can someone, send me some references which explains some of the reasons why the bond lengths fitted in EXAFS would be different from that fitted in XRD (assuming that we implemented the crystal model predicted by XRD correctly in Artemis)? I would really appreciate this! Sincerely -- Joseph Washington Research Assistant Department of Physics North Carolina State University 431 Riddick Hall Raleigh, NC 27695-8202 email: jswashin(a)ncsu.edu

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Re: [Ifeffit] Path degeneracy modification in feffNNN.dat
by Frenkel, Anatoly 20 Nov '09

20 Nov '09

It takes it from N. Anatoly ----- Original Message ----- From: ifeffit-bounces(a)millenia.cars.aps.anl.gov <ifeffit-bounces(a)millenia.cars.aps.anl.gov> To: ifeffit(a)millenia.cars.aps.anl.gov <ifeffit(a)millenia.cars.aps.anl.gov> Sent: Fri Nov 20 18:57:29 2009 Subject: Re: [Ifeffit] Path degeneracy modification in feffNNN.dat Hi ｔｈｅｒｅ, I have a general question about Artemis. I am going to split a degenerated path with degeneracy N=8 into twoｓ. I noticed that by cloning the path, the "N" in path math expression parameters was halved as "4". However, the degeneracy number in feffNNN.dat remains as "8". For fitting, where will Artemis exactly get this information? Or maybe I　ｓｈｏｕｌｄ　ｍｏｄｉｆｙ　ｆｅｆｆＮＮＮ．ｄａｔ　ｍａｎｕａｌｌｙ？　　Ｔｈａｎｋｓ　ｆｏｒ　ｙｏｕｒ　ｒｅｓｐｏｎｓｅ！＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝Ｄｒ．　Ｙｉｎｇ　ＺｏｕＲｅｓｅａｒｃｈ　Ａｓｓｏｃｉａｔｅ，ＵＷＭ／Ｐｈｙｓｉｃｓ，１９００　Ｅ．　Ｋｅｎｗｏｏｄ　Ｂｌｖｄ，Ｍｉｌｗａｕｋｅｅ，　ＷＩ５３２１７＝＝＝＝＝＝＝＝＝＝＝＝＝＝ _______________________________________________ Ifeffit mailing list Ifeffit(a)millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

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Re: [Ifeffit] Path degeneracy modification in feffNNN.dat
by Ying Zou 20 Nov '09

20 Nov '09

Hi ｔｈｅｒｅ, I have a general question about Artemis. I am going to split a degenerated path with degeneracy N=8 into twoｓ. I noticed that by cloning the path, the "N" in path math expression parameters was halved as "4". However, the degeneracy number in feffNNN.dat remains as "8". For fitting, where will Artemis exactly get this information? Or maybe I　ｓｈｏｕｌｄ　ｍｏｄｉｆｙ　ｆｅｆｆＮＮＮ．ｄａｔ　ｍａｎｕａｌｌｙ？　　Ｔｈａｎｋｓ　ｆｏｒ　ｙｏｕｒ　ｒｅｓｐｏｎｓｅ！＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝Ｄｒ．　Ｙｉｎｇ　ＺｏｕＲｅｓｅａｒｃｈ　Ａｓｓｏｃｉａｔｅ，ＵＷＭ／Ｐｈｙｓｉｃｓ，１９００　Ｅ．　Ｋｅｎｗｏｏｄ　Ｂｌｖｄ，Ｍｉｌｗａｕｋｅｅ，　ＷＩ５３２１７＝＝＝＝＝＝＝＝＝＝＝＝＝＝

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