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

Re: [Ifeffit] problem with E0 (enot) parameters
by joshua jason kas 20 Jun '09

20 Jun '09

As Anatoly mentioned, feff6 overestimates e0 (the Fermi energy). This is at least partially due to the use of overlapped atomic potential. The problem is fixed when the self-consistent potentials are used in feff8. If no self-consistency is used, I believe feff6 and feff8 give very similar results. Josh > From: "Frenkel, Anatoly" <frenkel(a)bnl.gov> > Subject: Re: [Ifeffit] problem with E0 (enot) parameters > To: "XAFS Analysis using Ifeffit" <ifeffit(a)millenia.cars.aps.anl.gov>, > "XAFS Analysis using Ifeffit" <ifeffit(a)millenia.cars.aps.anl.gov> > Message-ID: > <CCBF39F82283424BBB90EA208CD9DE80EBB710(a)exchangemb5.bnl.gov> > Content-Type: text/plain; charset="iso-8859-1" > > Just a comment, to add some sanity in this discussion: > > FEFF6 is overestimating delta E0 for Pt and a few other metals. I > forgot the reason but it could be the cause of a problem. > I think FEFF8 is doing a better job. Fortunately - and it was checked - > no other problems occur, just E0 values change, when one usees FEFF8 > instead of FEFF6 in most cases. > > Anatoly > > > ________________________________ > > From: ifeffit-bounces(a)millenia.cars.aps.anl.gov on behalf of Kropf, Arthur Jeremy > Sent: Fri 6/19/2009 3:41 PM > To: XAFS Analysis using Ifeffit > Subject: Re: [Ifeffit] problem with E0 (enot) parameters > > > > With the very strong white lines at the L3 edges of oxidized Pt, W, Ir, > etc., there is no reason to assume that Eo is on the lower energy side > of the peak. > > Jeremy Kropf > >> -----Original Message----- >> From: ifeffit-bounces(a)millenia.cars.aps.anl.gov >> [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf >> Of Zajac, Dariusz A. >> Sent: Friday, June 19, 2009 9:45 AM >> To: XAFS Analysis using Ifeffit >> Subject: Re: [Ifeffit] problem with E0 (enot) parameters >> >> Hi Scott, >> I am afraid that E0 jumps over the edge - see bmp's in the >> attachment (files with enot_12 means E0=12...). Hovewer 12 eV >> is still less than >> k=3 (the starting k value). Can it influence? I did also once >> more fit with R from 1.7 to 4A. Fits of first 2 peaks are >> identical - you can see in the attachment too... >> I hope you and anyone from the mailing list don't mind that I >> am attaching so many files... >> >> cheers >> darek >> >>> -----Original Message----- >>> From: ifeffit-bounces(a)millenia.cars.aps.anl.gov >>> [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf >> Of Scott >>> Calvin >>> Sent: Friday, June 19, 2009 2:49 PM >>> To: XAFS Analysis using Ifeffit >>> Subject: Re: [Ifeffit] problem with E0 (enot) parameters >>> >>> >>> Hi Darek, >>> >>> OK, so if the K, H, and O don't affect the fit much for the C and N, >>> and the K, H, and O are returning nonsensical values, then a logical >>> possibility is that the E0's for C and N are correct. If you >> add 12 eV >>> to the E0 you chose in Athena, where in the spectrum does it >> fall? Is >>> it still before the white line? If so, it seems to me you >> don't have a >>> problem. If not, then we have to ponder further. >>> >>> --Scott Calvin >>> Sarah Lawrence College >>> >>> On Jun 19, 2009, at 8:28 AM, Zajac, Dariusz A. wrote: >>> >>>> Hi Scott, >>>> look also at H and O, >>>> but for me and for this fit important are only W-C and W-C-N >>> bondings. >>>> This sample is an reference sample for other cyano-brigded >> networks. >>>> So >>>> you suggest to focuse on K ions? how can it help with first >>> 2 peaks? K >>>> is at ~5A. >>>> I have analysed in larger R space only to see how the >>> spectrum behave. >>>> contribution from K, O etc. at k highers than 5A is for me >> too low to >>>> analyse it resonable for such compound. >>>> I have attached in the previus post the last version of results. >>>> Anyway, >>>> enots for C and N do not change if I am enlarging R region >> (when I am >>>> including next paths, also for K). >>>> about material I am quite sure ;) and crystal structure is from >>>> literature >>>> >>>> in the attachment you will find bmp file of the fit: data, >> fit, bkg >>>> and K path. >>>> fitting ranges k(3-15) R(1.7-6) dk 2 dr 0.5, phase >> correction - first >>>> C >>>> >>>> cheers >>>> darek >>>> >>> >>> _______________________________________________ >>> Ifeffit mailing list >>> Ifeffit(a)millenia.cars.aps.anl.gov >>> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit >>> >> > > _______________________________________________ > Ifeffit mailing list > Ifeffit(a)millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > > > > > > ------------------------------ > > Message: 3 > Date: Sat, 20 Jun 2009 10:37:09 +0200 > From: "Zajac, Dariusz A." <dariusz.zajac(a)desy.de> > Subject: [Ifeffit] ODP: problem with E0 (enot) parameters > To: "XAFS Analysis using Ifeffit" <ifeffit(a)millenia.cars.aps.anl.gov> > Message-ID: <35E004AD6290A7438FCA34BBF325F4160C57F8(a)ADXV2.win.desy.de> > Content-Type: text/plain; charset="iso-8859-2" > > Dear Jeremy, > thanks for your reply. This fits to my results and to my "feeling", but is any physical meaning behind it? > cheers > darek > > > > -----Wiadomo?? oryginalna----- > Od: ifeffit-bounces(a)millenia.cars.aps.anl.gov w imieniu Kropf, Arthur Jeremy > Wys?ano: Pt 2009-06-19 21:41 > Do: XAFS Analysis using Ifeffit > Temat: Re: [Ifeffit] problem with E0 (enot) parameters > > With the very strong white lines at the L3 edges of oxidized Pt, W, Ir, > etc., there is no reason to assume that Eo is on the lower energy side > of the peak. > > Jeremy Kropf > >> -----Original Message----- >> From: ifeffit-bounces(a)millenia.cars.aps.anl.gov >> [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf >> Of Zajac, Dariusz A. >> Sent: Friday, June 19, 2009 9:45 AM >> To: XAFS Analysis using Ifeffit >> Subject: Re: [Ifeffit] problem with E0 (enot) parameters >> >> Hi Scott, >> I am afraid that E0 jumps over the edge - see bmp's in the >> attachment (files with enot_12 means E0=12...). Hovewer 12 eV >> is still less than >> k=3 (the starting k value). Can it influence? I did also once >> more fit with R from 1.7 to 4A. Fits of first 2 peaks are >> identical - you can see in the attachment too... >> I hope you and anyone from the mailing list don't mind that I >> am attaching so many files... >> >> cheers >> darek >> >>> -----Original Message----- >>> From: ifeffit-bounces(a)millenia.cars.aps.anl.gov >>> [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf >> Of Scott >>> Calvin >>> Sent: Friday, June 19, 2009 2:49 PM >>> To: XAFS Analysis using Ifeffit >>> Subject: Re: [Ifeffit] problem with E0 (enot) parameters >>> >>> >>> Hi Darek, >>> >>> OK, so if the K, H, and O don't affect the fit much for the C and N, >>> and the K, H, and O are returning nonsensical values, then a logical >>> possibility is that the E0's for C and N are correct. If you >> add 12 eV >>> to the E0 you chose in Athena, where in the spectrum does it >> fall? Is >>> it still before the white line? If so, it seems to me you >> don't have a >>> problem. If not, then we have to ponder further. >>> >>> --Scott Calvin >>> Sarah Lawrence College >>> >>> On Jun 19, 2009, at 8:28 AM, Zajac, Dariusz A. wrote: >>> >>>> Hi Scott, >>>> look also at H and O, >>>> but for me and for this fit important are only W-C and W-C-N >>> bondings. >>>> This sample is an reference sample for other cyano-brigded >> networks. >>>> So >>>> you suggest to focuse on K ions? how can it help with first >>> 2 peaks? K >>>> is at ~5A. >>>> I have analysed in larger R space only to see how the >>> spectrum behave. >>>> contribution from K, O etc. at k highers than 5A is for me >> too low to >>>> analyse it resonable for such compound. >>>> I have attached in the previus post the last version of results. >>>> Anyway, >>>> enots for C and N do not change if I am enlarging R region >> (when I am >>>> including next paths, also for K). >>>> about material I am quite sure ;) and crystal structure is from >>>> literature >>>> >>>> in the attachment you will find bmp file of the fit: data, >> fit, bkg >>>> and K path. >>>> fitting ranges k(3-15) R(1.7-6) dk 2 dr 0.5, phase >> correction - first >>>> C >>>> >>>> cheers >>>> darek >>>> >>> >>> _______________________________________________ >>> Ifeffit mailing list >>> Ifeffit(a)millenia.cars.aps.anl.gov >>> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit >>> >> > > _______________________________________________ > Ifeffit mailing list > Ifeffit(a)millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > > > > > ------------------------------ > > Message: 4 > Date: Sat, 20 Jun 2009 12:44:34 +0200 > From: Stefan Mangold <stefan.mangold(a)iss.fzk.de> > Subject: Re: [Ifeffit] problem with E0 (enot) parameters > To: XAFS Analysis using Ifeffit <ifeffit(a)millenia.cars.aps.anl.gov> > Message-ID: <6F3358E1-7C2C-4FA2-B3B3-AD9FF7B0C5F3(a)iss.fzk.de> > Content-Type: text/plain; charset="iso-8859-1" > > Please do not attach 10 Mb of data on your Mails. Just send an Link to > an Web-space with your e-mail. People can then download the stuff if > needed. > > Best regards > > Stefan > > Am 19.06.2009 um 16:44 schrieb Zajac, Dariusz A.: > >> Hi Scott, >> I am afraid that E0 jumps over the edge - see bmp's in the attachment >> (files with enot_12 means E0=12...). Hovewer 12 eV is still less than >> k=3 (the starting k value). Can it influence? I did also once more fit >> with R from 1.7 to 4A. Fits of first 2 peaks are identical - you can >> see >> in the attachment too... >> I hope you and anyone from the mailing list don't mind that I am >> attaching so many files... >> >> cheers >> darek >> >>> -----Original Message----- >>> From: ifeffit-bounces(a)millenia.cars.aps.anl.gov >>> [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf >>> Of Scott Calvin >>> Sent: Friday, June 19, 2009 2:49 PM >>> To: XAFS Analysis using Ifeffit >>> Subject: Re: [Ifeffit] problem with E0 (enot) parameters >>> >>> >>> Hi Darek, >>> >>> OK, so if the K, H, and O don't affect the fit much for the C and N, >>> and the K, H, and O are returning nonsensical values, then a logical >>> possibility is that the E0's for C and N are correct. If you >>> add 12 eV >>> to the E0 you chose in Athena, where in the spectrum does it fall? Is >>> it still before the white line? If so, it seems to me you >>> don't have a >>> problem. If not, then we have to ponder further. >>> >>> --Scott Calvin >>> Sarah Lawrence College >>> >>> On Jun 19, 2009, at 8:28 AM, Zajac, Dariusz A. wrote: >>> >>>> Hi Scott, >>>> look also at H and O, >>>> but for me and for this fit important are only W-C and W-C-N >>> bondings. >>>> This sample is an reference sample for other cyano-brigded networks. >>>> So >>>> you suggest to focuse on K ions? how can it help with first >>> 2 peaks? K >>>> is at ~5A. >>>> I have analysed in larger R space only to see how the >>> spectrum behave. >>>> contribution from K, O etc. at k highers than 5A is for me too low >>>> to >>>> analyse it resonable for such compound. >>>> I have attached in the previus post the last version of results. >>>> Anyway, >>>> enots for C and N do not change if I am enlarging R region (when I >>>> am >>>> including next paths, also for K). >>>> about material I am quite sure ;) and crystal structure is from >>>> literature >>>> >>>> in the attachment you will find bmp file of the fit: data, fit, bkg >>>> and >>>> K path. >>>> fitting ranges k(3-15) R(1.7-6) dk 2 dr 0.5, phase correction - >>>> first C >>>> >>>> cheers >>>> darek >>>> >>> >>> _______________________________________________ >>> Ifeffit mailing list >>> Ifeffit(a)millenia.cars.aps.anl.gov >>> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit >>> >> < >> K4W >> (CN >> )8_enot_12 >> .bmp >>> >> < >> K4W >> (CN >> )8_enot_0.bmp><K4WCN8_b.apj><K4W(CN)8_2.bmp><K4W(CN)8_2q.bmp><mime- >> attachment.txt> > > -- > Dr. Stefan Mangold > Institut f?r Synchrotronstrahlung > Forschungszentrum Karlsruhe > Tel.: +49-7247-826073 > >

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Re: [Ifeffit] Primitive unit cell from .cif file
by joshua jason kas 19 Jun '09

19 Jun '09

Hi Bruce, > I don't really understand what you are driving at, but it seems as > though you want to express Diamond as a simple cubic cell with a two > atom basis? Yes, that would be the case for diamond, but for an arbitrary crystal structure specified as in a .cif I would like to find the primitive cell, i.e. the unit cell of smallest volume. > I don't really understand how that > will save you time in > abinit, but, of course, I am not a crystallographer.... Smaller volume means less bands to obtain the same energy range. > PS. Doesn't abinit understand crystal symmetry? Maybe. I couldn't get it to reproduce the diamond structure using only one atom in the cell, but I haven't been using it for very long, and will probably go to the abinit list for this. > Why can't you just tell it that it's diamond and has the symmetry of > diamond? For our application, we can't really use the symmetry at this point. Would be good if we can in the future, but for now we really need input that includes all atoms in the primitive unit cell. Again, thanks to everyone for your time. I hope this was not too far out in left field for this mailing list. Apologies if it was. Josh Kas > > -- > Bruce Ravel ----------------------------------- bravel(a)bnl.gov > > National Institute of Standards and Technology > Synchrotron Methods Group at Brookhaven National Laboratory > Building 535A > Upton NY, 11973 > > My homepage: http://cars9.uchicago.edu/~ravel > EXAFS software: http://cars9.uchicago.edu/~ravel/software/exafs/ > > > > > -----Original Message----- > From: ifeffit-bounces(a)millenia.cars.aps.anl.gov on behalf of joshua jason kas > Sent: Thu 6/18/2009 2:41 PM > To: ifeffit(a)millenia.cars.aps.anl.gov > Subject: Re: [Ifeffit] Primitive unit cell from .cif file > > Thanks everyone for your suggestions! I have tried the following things. > I used atoms (webATOMS) to generate a p1.inp file using diamond as an > example, but this gives me the conventional cell with 8 atoms in > it instead of the 2 atom primitive cell. Am I doing something wrong? > The input file came from the atoms database and the output is as follows: > > * > * "F d -3 m" appears in the International Tables with > * multiple choices of origin. If the atoms list seems wrong, you > * should use a shift vector of: > * -0.125, -0.125, -0.125 > * > * > ! This p1.inp file was generated by WebAtoms 1.8 (Atoms 3.0beta10) > ! Atoms written by and copyright (c) Bruce Ravel, 1998-2001 > title = name: diamond > title = formula: C > title = sites: C1 > title = refer1: Kittel, ISSP > title = refer2: > title = schoen: > title = notes1: diamond structure > space p 1 ! original space group: F d -3 m > a = 3.5670 b = 3.5670 c = 3.5670 > alpha = 90.0 beta = 90.0 gamma = 90.0 > core = C1_1 edge = K rmax = 6.0 > atoms > ! elem x y z tag occ > C 0.12500 0.12500 0.12500 C1_1 1 > C 0.12500 0.62500 0.62500 C1_2 1 > C 0.62500 0.12500 0.62500 C1_3 1 > C 0.62500 0.62500 0.12500 C1_4 1 > C 0.87500 0.37500 0.37500 C1_5 1 > C 0.87500 0.87500 0.87500 C1_6 1 > C 0.37500 0.37500 0.87500 C1_7 1 > C 0.37500 0.87500 0.37500 C1_8 1 > > I also tried the Mercury demo, but all editing features are disabled. > > I will try Diamond now. > > Just to give some motivation here, I am working with abinit (along with > feff) to produce optical spectra. If I use a conventional cell, the > calculations become much more time consuming, so ideally I want to use a > primitive cell. > Thanks again for all your help! > Josh > >> Hi Josh, >> You may try Diamond Demo version which is free. >> >> http://www.crystalimpact.com/diamond/download.htm > I will give this a try. > > >> >> Hi Josh, >> >> If I understand your question, I think that Atoms does what you want. Running the command line tool as "atoms -p" turns the attached cif file into the attached "p1.inp" file. You can do the same thing inside of Artemis using "write special output" in the Theory menu. > >> >> B >> >> -- >> Bruce Ravel ----------------------------------- bravel(a)bnl.gov >> >> National Institute of Standards and Technology >> Synchrotron Methods Group at Brookhaven National Laboratory >> Building 535A >> Upton NY, 11973 >> >> My homepage: http://cars9.uchicago.edu/~ravel >> EXAFS software: http://cars9.uchicago.edu/~ravel/software/exafs/ >> >> >> >> >> -----Original Message----- >> From: ifeffit-bounces(a)millenia.cars.aps.anl.gov on behalf of joshua jason kas >> Sent: Wed 6/17/2009 2:16 PM >> To: ifeffit(a)millenia.cars.aps.anl.gov >> Subject: [Ifeffit] Primitive unit cell from .cif file >> >> Hi everyone, >> I was wondering if there is a simple (free) utility for producing a >> primitive cell (not conventional) from an asymmetric cell and space group. >> Basically, I want to be able to easily go from a crystallographic >> information file to a primitive unit cell. I know that there are ways to >> do this within applications like material studio, but these are expensive. >> Any help would be appreciated. >> Thanks, >> Josh Kas >> _______________________________________________ >> Ifeffit mailing list >> Ifeffit(a)millenia.cars.aps.anl.gov >> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit >> >> >>

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Radial distribution
by Eugenio Otal 18 Jun '09

18 Jun '09

Hi Shelly, thanks, I will try this. Cheers, euG 8<- - - - - - 8<- - - - - - 8<- - - - - - 8<- - - - - -

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Radial distribution
by Eugenio Otal 18 Jun '09

18 Jun '09

Hi, I performed EXAFS simulation and want to obtain the radial distribution of the signal. I tried with athena but I cannot process it like experimental signal. Is there any trick to transform the signal into radial distribution? Thanks, euG 8<- - - - - - 8<- - - - - - 8<- - - - - - 8<- - - - - -

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Primitive unit cell from .cif file
by Eugenio Otal 17 Jun '09

17 Jun '09

Josh, you can also try with Mercury, has a free version at: http://www.ccdc.cam.ac.uk/products/mercury/ Hope it helps, euG 8<- - - - - - 8<- - - - - - 8<- - - - - - 8<- - - - - - Hi Josh, You may try Diamond Demo version which is free. http://www.crystalimpact.com/diamond/download.htm Good luck, Mengqiang Zhu ----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html ---- Original message ---- >*Date: Wed, 17 Jun 2009 11:16:49 -0700 (PDT) *>*From: ifeffit-bounces at millenia.cars.aps.anl.gov <http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit> (on behalf of joshua jason kas <hebhop at u.washington.edu <http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit>>) *>*Subject: [Ifeffit] Primitive unit cell from .cif file *>*To: ifeffit at millenia.cars.aps.anl.gov <http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit> *>* *>*Hi everyone, *>*I was wondering if there is a simple (free) utility for producing a *>*primitive cell (not conventional) from an asymmetric cell and space group. *>*Basically, I want to be able to easily go from a crystallographic *>*information file to a primitive unit cell. I know that there are ways to *>*do this within applications like material studio, but these are expensive. *>*Any help would be appreciated. *>*Thanks, *>*Josh Kas *>*_______________________________________________ *>*Ifeffit mailing list *>*Ifeffit at millenia.cars.aps.anl.gov <http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit> *>*http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit *

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Primitive unit cell from .cif file
by joshua jason kas 17 Jun '09

17 Jun '09

Hi everyone, I was wondering if there is a simple (free) utility for producing a primitive cell (not conventional) from an asymmetric cell and space group. Basically, I want to be able to easily go from a crystallographic information file to a primitive unit cell. I know that there are ways to do this within applications like material studio, but these are expensive. Any help would be appreciated. Thanks, Josh Kas

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Re: [Ifeffit] how to reduce the core-hole lifetime broadening in feff8.2
by joshua jason kas 12 Jun '09

12 Jun '09

> And yet, the documentation for the CORRECTIONS keyword says: > > "The real energy shift vrcorr moves E0 in the final \chi(k) and > the imaginary energy shift vicorr adds broadening to the > result. The real energy shift is useful to correct the error in > FEFF's Fermi level estimate and the imaginary part can be used to > correct for experimental resolution or errors in the core-hole > lifetime." > > And a couple of sentences later: > > "The imaginary energy is typically used to correct for instrument > broadening or as a correction to the mean free path calculated by > feff." > > Perhaps the document should be updated to explain more clearly what > CORRECTIONS actually does. Thank you Bruce. I will try to clear up the documentation. Let me state more clearly how these two cards can be used to change the broadening of the spectrum. In the EXCHANGE card, the user can use negative values to offset the core hole broadening. The CORRECTIONS card can only be used to add to the total (previous) broadening, which is given by the half width at half max, Gamma_CH/2 + vi, where vi is the broadening from the EXCHANGE card and Gamma_CH is the core hole broadening. The benefit of using the CORRECTIONS card is that it is very fast since you can skip the matrix inversion for the FMS calculation. Thus a good way to use the two cards together is to reduce the broadening via EXCHANGE by a bit too much (use an overestimate as a first try), then use the CORRECTIONS card to fine tune the broadening. Cheers, Josh correctly. > Bruce Ravel ------------------------------------ bravel(a)bnl.gov > > National Institute of Standards and Technology > Synchrotron Methods Group at NSLS --- Beamlines U7A, X24A, X23A2 > Building 535A > Upton NY, 11973 > > My homepage: http://xafs.org/BruceRavel > EXAFS software: http://cars9.uchicago.edu/~ravel/software/exafs/ > > > > ------------------------------ > > _______________________________________________ > Ifeffit mailing list > Ifeffit(a)millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > > > End of Ifeffit Digest, Vol 76, Issue 8 > ************************************** >

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how to reduce the core-hole lifetime broadening in feff8.2
by joshua jason kas 11 Jun '09

11 Jun '09

Hi Tony, As mentioned already, you can use the EXCHANGE card with negative values to reduce the core-hole broadening. Note however that this will not work with the CORRECTIONS card. Josh Kas > Message: 1 > Date: Thu, 11 Jun 2009 05:58:53 -0700 (PDT) > From: tony vitova <tony_vitova(a)yahoo.com> > Subject: [Ifeffit] how to reduce the core-hole lifetime broadening in > feff8.2 > To: Ifeffit List <ifeffit(a)millenia.cars.aps.anl.gov> > Message-ID: <204685.79014.qm(a)web54505.mail.re2.yahoo.com> > Content-Type: text/plain; charset="iso-8859-1" > > Dear?all, > ? > Could somebody give me a hint how to reduce the core-hole lifetime broadening in feff8.2? Do I?need to change the source code? I have partial fluorescence yield XANES spectrum whose White Line is narrow than the one in the calculation. > ? > Thanks for any help > ? > Tonya > > > >

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how to reduce the core-hole lifetime broadening in feff8.2
by tony vitova 11 Jun '09

11 Jun '09

Dear all, Could somebody give me a hint how to reduce the core-hole lifetime broadening in feff8.2? Do I need to change the source code? I have partial fluorescence yield XANES spectrum whose White Line is narrow than the one in the calculation. Thanks for any help Tonya

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Re: [Ifeffit] how to reduce the core-hole lifetime broadening in feff8.2
by tony vitova 11 Jun '09

11 Jun '09

Hi Janine and Bruce, Thanks a lot! I didn't think that the EXCHANGE card might take and negative values... Tonya --- On Thu, 6/11/09, Janine GRATTAGE <janine.grattage(a)esrf.fr> wrote: From: Janine GRATTAGE <janine.grattage(a)esrf.fr> Subject: Re: [Ifeffit] how to reduce the core-hole lifetime broadening in feff8.2 To: "XAFS Analysis using Ifeffit" <ifeffit(a)millenia.cars.aps.anl.gov> Date: Thursday, June 11, 2009, 5:29 PM Hi Tonya, I use the EXCHANGE card to reduce the applied broadening in my spectra. If you set the third parameter in the card to a number less than zero (up to about -5 in my experience) then the broadening is reduced and you can calculate high resolution type XANES spectra. This applies only to some inherent limit in the calculations where further reducing the parameter has no effect. You can look up the EXCHANGE card on the feff wiki as it also can be used to change the exchange model and the position of the Fermi level. Hope that helps you! Janine tony vitova wrote: > Dear all, > > Could somebody give me a hint how to reduce the core-hole lifetime > broadening in feff8.2? Do I need to change the source code? I have > partial fluorescence yield XANES spectrum whose White Line is narrow > than the one in the calculation. > > Thanks for any help > > Tonya > > > ------------------------------------------------------------------------ > > _______________________________________________ > Ifeffit mailing list > Ifeffit(a)millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > -- Dr Janine GRATTAGE Postdoctoral Fellow, ID26 European Synchrotron Radiation Facility (ESRF) Sector 26, BP 220 6, rue Jules Horowitz, 38043 Grenoble, Cedex 9, FRANCE Tel: +33(0)4 38 88 19 30 Email: janine.grattage(a)esrf.fr _______________________________________________ Ifeffit mailing list Ifeffit(a)millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

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