[Ifeffit] Postdoctoral position at Yeshiva University

Dear IFEFFIT subscribers: Please find here the info about the job opening: Postdoctoral position at Yeshiva University Physics Department of Yeshiva University in New York City has immediate opening for a postdoctoral research associate position. The postdoc will investigate thermal, structura

Re: [Ifeffit] McMaster correction

Hi Scott, I maybe misunderstood your question but let me comment on it the way I see the problem. First, chi(k) is defined only above k=0 (E=E0), of course, and its defined as mu=mu_o*(1+chi(k)). chi(k) results from the scattering electron wave function being non-monotonic and is stripped of

Re: [Ifeffit] Athena (Question about LC fitting)

I meant "fit" the standards to the unknown, and I also noticed that Bruce had already replied to the same question below. Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Frenkel, Anatoly Sent: Sun 5/15/2011 2:34 PM To: XAFS Anal

Re: [Ifeffit] Athena (Question about LC fitting)

It is really important to have the data for the "unknown" sample and for "standards" correctly aligned in energy. That means that all of them should be measured in an experiment with the same sample located in the "reference" position between the transmitted and reference beam detectors. The abs

Re: [Ifeffit] What does FEFF stand for?

You are both mistaken, but do not check what FEFF is on Urban Dictionary, as it is inappropriate. Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Ravel, Bruce Sent: Tue 5/10/2011 3:16 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit]

Re: [Ifeffit] Strategy to obtain cofigurationally averaged EXAFS fromMD simulations

The answer depends, really, on what you want to accomplish. There are several approaches: 1. Full atom-by-atom calculations of EXAFS following an MD trajectory: Riscioni, et al, PRB 83, 115409 (2011). This is required if you have disordered clusters, for example, and your electronic contributio

[Ifeffit] EXAFS art

This is a beautiful piece of EXAFS art: http://www.offthebend.com/2010/12/fine-art-nassos-daphnis-and-his-shapes.html Anatoly <>___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

Re: [Ifeffit] Fe in glassy ceramics

Diffraction anomalous fine structure seems to the most appropriate method here. Anatoly Frenkel Sent from my mobile phone, please forgive typos. -Original message- From: Andrei Shiryaev To: ifeffit@millenia.cars.aps.anl.gov Sent: Wed, Feb 16, 2011 12:52:38 GMT+00:00 Subject: [Ifeffit

Re: [Ifeffit] Distortion of transmission spectra due to particlesize

You are right about the amplitude factor: it should change. The ln(1+x/2) is not the full story, since x is the exponent: x= exp(-mu*t) and when mu*t is small (thin samples), x is not, and vice versa. More accurate expansion of ln(1+x/2) in the limit of thick and thin samples shows that mu_measu

Re: [Ifeffit] Distortion of transmission spectra due to particlesize

> down on normalization. That will have to wait. > > Jeremy > > > From: ifeffit-boun...@millenia.cars.aps.anl.gov > [mailto:ifeffit-boun...@millenia.cars.aps.anl.gov] On Behalf Of Frenkel, > Anatoly > Sent: Wednesday, November 24, 2010 1:33 PM > To: XAFS Analysis usin

Re: [Ifeffit] Distortion of transmission spectra due to particlesize

Jeremy: In your simulation, "(c) 1/2 original, 1/2 nothing (a large "pinhole")" it appears that chi(k) is half intensity of the original spectrum. Does it mean that when the pinhole is present, EXAFS wiggles are half of the original ones in amplitude but the edge step remains the same? Or, equi

Re: [Ifeffit] Transmission EXAFS sample

That's probably how they discovered graphene, by trying to make exafs sample. Anatoly Sent from my mobile phone, please forgive typos. -Original message- From: Scott Calvin To: XAFS Analysis using Ifeffit Sent: Fri, Nov 19, 2010 18:30:37 GMT+00:00 Subject: Re: [Ifeffit] Transmission

Re: [Ifeffit] Asymmetric error bars in IFeffit

Scott, It is a strange result. Suppose you fit a bulk metal foil and vary the 1nn coordination number. You will not get 12 +/- 1000. You will get about 12 +/- 0.3 depending on the data quality and the k range, and on the amplitude factor you fix constant. Then, suppose you take your formula for

Re: [Ifeffit] Asymmetric error bars in IFeffit

instance trying to change Al for Au or an oxide for a metal. Brings back memories, not all of them fond :-) mam - Original Message - From: Frenkel, Anatoly <mailto:fren...@bnl.gov> To: ifeffit@millenia.cars.aps.anl.gov Sent: Friday, Octo

Re: [Ifeffit] Asymmetric error bars in IFeffit

On a related subject, now I understand why we use the concept of chemical transferability of amplitudes and phases by recycling the same FEFF path for different systems. The true reason is historic: back then it took one hour for one FEFF calculation Anatoly ___

Re: [Ifeffit] Multiple scattering paths in fitting

For relationships between sigma2 for MS and SS paths, some are listed in the Appendix to this article: P. Shanthakumar, et al, Physical Review B 74, 174103 (2006). Anatoly <>___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://mill

Re: [Ifeffit] Multiple scattering paths in fitting

For bond angles, this google search would be helpful: buckling angle multiple scattering xafs Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Abhijeet Gaur Sent: Thu 10/7/2010 3:21 AM To: ifeffit Subject: [Ifeffit] Multiple scattering pa

Re: [Ifeffit] Ifeffit Digest, Vol 91, Issue 28

It is because you made delta E0=0, but the fit gave you delta E0=8. Since the fit agrees with the data in k-space at low wavenumbers (I assume), then the signal with delta E0=0 should not, and vice versa. Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov

[Ifeffit] Advanced EXAFS analysis course in Brooikhaven, Nov 4-6, 2010

Dear IFEFFIT list subscribers: Those of you who may be interested in the XAFS short course at BNL (Nov 4-6, 2010), please find the application form available online: http://www.nsls.bnl.gov/newsroom/events/workshops/2010/exafs/

Re: [Ifeffit] debye function

Just to add: These procedures, described in that article, can be easily implemented in Mathematica. Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Ravel, Bruce Sent: Tue 8/24/2010 1:23 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifef

Re: [Ifeffit] Haha

And for the red curve, someone forgot the sample... Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Heinz-Eberhard Mahnke Sent: Sun 8/15/2010 12:04 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Haha Hi, nice spectrum. Why is th

Re: [Ifeffit] C and N NEXAFS normalization

I have a terrible feeling that it may be one of those cases where FEFF6 gives a large E0 shift when FEFF8 has a normal shift, the rest of the results being the same. See Josh Kas's explanation of this issue a while ago. Anatoly From: ifeffit-boun...@millen

Re: [Ifeffit] fitting

CeO2, but...for me there is something wrong since the Athena fitting, because there are too many peaks below the main one, and specially below 1 A. Am I right or not? Maria Elena 2010/5/13 Frenkel, Anatoly There is a large number of articles explaining how to fit CeO2 incl

Re: [Ifeffit] fitting

There is a large number of articles explaining how to fit CeO2 including discussions why multi-electron excitatoins complicate the fit, and some of those authors (e.g., A. Soldatov, but also M. Benfatto) propose first principle methods that account for those. Some papers even show that ignoring

Re: [Ifeffit] Debye model on Artemis

Kleber, Correlated Debye Model (CDM) was proposed by Sevillano, Meuth and Rehr in 1979 in a Phys Rev B artcile. It also shows how to find sigma2(T) from the CDM- and also from Einsten model, by the way. In the former case, you take phonon density of states in Debye approximation (where it is p

Re: [Ifeffit] energy resolution

This is a quote from Joseph Dvorak' report on energy resolution measurements at the NSLS beamlines: The energy resolution was measured as follows. A Si 220 crystal was used as an analyzer crystal. This was placed in the hutch in near back reflection condition (87 deg inc). The reflected x-ray

Re: [Ifeffit] Differences between fluorescence and transmission of thesame sample

What can be done in this case, is not to use either flourescence or transmission data, - because both are bad by the reasons Bruce explained - but use corrections, if you cannot change your experimental geometry (different concentration of the sample or different thickness or different reactor c

Re: [Ifeffit] Logicused in Artemis to do the error minimization

I meant that error bars are related to "standard deviations of the mean", not "standard deviations"... Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Frenkel, Anatoly Sent: Mon 3/8/2010 9:25 AM To: XAFS Analysis u

Re: [Ifeffit] Logicused in Artemis to do the error minimization

Bruce, Some time ago I was trying to find a reference (and failed) explaining the relationship between the error bar reported by the fitting algorithm of ifeffit and one standard deviation in the fitting parameter. From your reply below it appears that they are the same ("error bars reported b

Re: [Ifeffit] Bruce ayuda, problemas con athena

13, 2010 at 10:38 AM, Frenkel, Anatoly wrote: > Can't wait for a question in Russian. > Anatoly ??? ? ?? ? --Matt ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/m

Re: [Ifeffit] Bruce ayuda, problemas con athena

Can't wait for a question in Russian. Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Ravel, Bruce Sent: Sat 2/13/2010 10:52 AM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Bruce ayuda, problemas con athena On Friday 12 Februar

Re: [Ifeffit] (no subject)

There was a paper by J. Penner-Hahn et al. studying ZnCl2 by EXAFS and using it to demonstrate the quadrupole (1s-3d) transition by analyzing angular dependence of pre-edge features of Zn K-edge. You may contact him directly for exact reference. Anatoly From

Re: [Ifeffit] Fitting using Experimental standard

amp, but that may be just to make a "corrected" FT. Is that so? Otherwise, I suppose it should be possible to write a fake FEFF path file and read it in. I guess that's what you did. mam - Original Message - From: Frenkel, Anatoly <mailto:fren...@bnl

Re: [Ifeffit] Fitting using Experimental standard

of fitting to amp and phase. You feed it amp and phases which come from the FT program, also available at the website. The amp and phase files are simple 2-column ASCII, thus readable anywhere. mam - Original Message - From: "Frenkel, Anatoly" To: "XAFS Analysis

Re: [Ifeffit] Fitting using Experimental standard

I know of one very obscure conference proceeding describing what you are looking for. It was written during pre-Artemis times but the method can be used with Artemis, of course. A. I. Frenkel, M. Vairavamurthy, and M. Newville, A study of the coordination environment in aqueous cadmium-thiol c

Re: [Ifeffit] Lattice parameters: EXAFS vs. XRD

A correction to Matt's email: In random alloys, smaller size atoms and larger size atoms are at different average distances (measured by EXAFS and other local-structure-sensitive techniques, e.g., XRD/PDF) that are, respectively, smaller and larger than the distance between the average lattice p

Re: [Ifeffit] Lattice parameters: EXAFS vs. XRD

Big deal... We have final exams on Christmas... Anatoly Frenkel Yeshiva University From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Scott Calvin Sent: Fri 12/25/2009 1:04 PM To: XAFS Analysis using Ifeffit Subject: [Ifeffit] Lattice parameters: EXAFS

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. Th

Re: [Ifeffit] Path degeneracy modification in feffNNN.dat

It takes it from N. Anatoly - Original Message - From: ifeffit-boun...@millenia.cars.aps.anl.gov To: ifeffit@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.

Re: [Ifeffit] Bug in Athena?

Yay! Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Matt Newville Sent: Thu 11/19/2009 2:59 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Bug in Athena? Hi Scott On Thu, Nov 19, 2009 at 9:50 AM, Scott Calv

Re: [Ifeffit] Bug in Athena?

May be it is relevant... I use references to align the data in energy, not to measure energy shift between different samples, because the references may be (not always are though, but why to take chance...) inherently worse quality data compared to the bulk of the relevant standard compound that

Re: [Ifeffit] modeling anti-site disorder

another contraint, e.g., a known value of site occupancy of Ga (i.e., y = 0.2). Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Frenkel, Anatoly Sent: Sun 11/8/2009 12:15 PM To: XAFS Analysis using Ifeffit Subject: RE: [Ifeffit] modeling anti

Re: [Ifeffit] modeling anti-site disorder

I would make a feff.inp file corresponding to the Co as a central atom in CoGa in its original CsCl structure. Then, I would substitute all Ga atoms by Co (the two sites are crystallographically equivalent in the bcc lattice, and there is no need to do it separately for Cs and Cl sites). That wo

Re: [Ifeffit] edge height proportional to the molar density?

Look for the papers by Irit Sagi. We have done just these types of measurements of edge height to estimate molar density in metal proteins. It works for fluorescence as long as the concentration of absorber is low and the geometry of the experiment does not change between the samples. Anatoly

[Ifeffit] Two postdoctoral positions at Brookhaven

Dear IFEFFIT subscribers: Please pass these two job announcements to those colleagues who may be interested in these postdoctoral positions. Thank you very much, Anatoly ** Job #1: Postdoctoral position at Yeshiva University In September 2009, Physics Department of Yeshiva U

Re: [Ifeffit] new release of my software

It is when you take a bug from a pot and then put it back in the pot. Anatoly From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Julie Olmsted Cross Sent: Wed 7/1/2009 4:47 PM To: Ravel, Bruce; XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] new r

Re: [Ifeffit] problem with E0 (enot) parameters

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 chan

Re: [Ifeffit] Multiple data set fit

I don't think there is much published on that, so it is worth trying and see what you get. Anatoly -Original Message- From: ifeffit-boun...@millenia.cars.aps.anl.gov [mailto:ifeffit-boun...@millenia.cars.aps.anl.gov]on Behalf Of Debora Meira Sent: Friday, April 17, 2009 10:23 AM To: if

Re: [Ifeffit] huge S02 value ??

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: Sun, 5 Apr 2009 12:44:13 -0400 >From: ifeffit-boun...@millenia.cars.aps.anl.gov (on behalf of "Frenkel

Re: [Ifeffit] huge S02 value ??

Hi Mengqiang, I have done fits of aqueous solution of NiSO4 before and obtained S02 of 0.8 for the octahedrally coordinated Ni-O shell. You did not send the mu(E) data, just chi(k), so I was not able to compare my and your raw data fully, just in k-space. Here is what I found: my data is in pe

Re: [Ifeffit] Mixed Multiple scattering shell

Could be helpful: RbBr, KBr, RbCl, AgBr(x)Cl(1-x) etc.l: A. Frenkel, E. A. Stern, M. Qian, and M. Newville, Multiple - scattering x-ray-absorption fine-structure analysis and thermal expansion of alkali halides, Phys. Rev. B 48 , 12449 (1993). A. Frenkel, E. A. Stern, A. Voronel, M. Qian, an

Re: [Ifeffit] (no subject)

I would like to be proven wrong but my feeling is, without even knowing anything about this particular system, that one cannot observe Fe-Fe pair at that distance in such complex case. However, to approach it more rigorously, the first step would be to examine the relative "importance" factors

Re: [Ifeffit] SIXPACK

That has been my experience too. Or, in french: Cela a été mon expérience aussi. Anatoly -Original Message- From: ifeffit-boun...@millenia.cars.aps.anl.gov [mailto:ifeffit-boun...@millenia.cars.aps.anl.gov]on Behalf Of Matt Newville Sent: Thursday, February 12, 2009 1:11 PM To: bounif; Sa

Re: [Ifeffit] Lost second shell

Eugenio, Nice plots, and good data too, with a low amount of noize. It is indeed a very sad looking Er-O contribution and almost nothing else except for a small bump near 3 A where Zn-Zn appears in ZnO. For Er-O, the peak position is shifted to the right relative to a nominal Zn-O position in

Re: [Ifeffit] Lost second shell

Eugenio, The possibilities depend on the actual data at hand. Not seeing second shell is a relative term. Do you mean that you do not see it above noise? Then, technically, you cannot say that you do not have a second shell. Er may substitute for Zn and you will still have Er-Zn contribution

Re: [Ifeffit] small-screen version of Athena document

Bruce and Matt: When Athena and Artemis are completely moved to BlackBerry and iPhone, there will be a number of really nice options out there. For example, ringtones for a really bad fit should be made very unpleasant, and even more so, when Delta E0 is out of bounds, or r-factor is greater th

Re: [Ifeffit] Cumulant expansion fittings

Matt, it is a very nice explanation. Another way to think about the triangle inequality effect is to imagine a snapshot at the framework of atomic bonds in solid where they are all distorted from the underlying crystallographic lattice due to thermal vibrations. Imagine then N successive (100)

Re: [Ifeffit] Cumulant expansion fittings

m harmonic that the fourth cumulant alone is not enough. --Scott Calvin Sarah Lawrence College On Jan 21, 2009, at 10:11 PM, Frenkel, Anatoly wrote: > > Thus, I am pretty much convinced, unless there is some mistake in my > reasoning, that no case exists in 3D with a

Re: [Ifeffit] Cumulant expansion fittings

omputer precision of floating point numbers). The second option (often called a "histogram" approach in the Ifeffit world, and modeled somewhat after The GNXAS Approach) has been used successfully a number of times. --Matt > > On Jan 21, 2009, at 10:12 AM, Frenkel, Anatoly wrote: >

Re: [Ifeffit] Cumulant expansion fittings

Hi Scott, Third cumulant in your example will not be zero because this arrangement is symmetric only on the average. Locally, the interatomic pair potential (and the cumulants are the measures of the effective pair potential) which is the sum of the two potentials - between the interestitial a

Re: [Ifeffit] difference between Zn-Zn/Fe and Zn-Fe paths

Hashem, it is not very clear, give mode details for each fitting scheme. Anatoly -Original Message- From: ifeffit-boun...@millenia.cars.aps.anl.gov [mailto:ifeffit-boun...@millenia.cars.aps.anl.gov]on Behalf Of Hashem Stietiya Sent: Friday, January 16, 2009 12:13 PM To: ifeffit@milleni

Re: [Ifeffit] How to identify N and O atoms in the first coordinate

:36 -0500 >From: ifeffit-boun...@millenia.cars.aps.anl.gov (on behalf of "Frenkel, >Anatoly" ) >Subject: Re: [Ifeffit] How to identify N and O atoms in the first coordinate >To: "XAFS Analysis using Ifeffit" , > > >Dear Mengqiang, > >To the best

Re: [Ifeffit] How to identify N and O atoms in the first coordinate

Dear Mengqiang, To the best of my knowledge, in most cases Nitrogen cannot be discerned from Oxygen as a nearest neighbor since their scattering properties are similar. Thus, if you want to solve an "inverse" problem ("Which type of neighbors do I have") you cannot do it. However, if you belie

Re: [Ifeffit] Normalization of XANES spectra

Jens: This example may help you understand your problem: if compound a) has a small fraction of metal Cu mixed with a large fraction of oxidized Cu, while a compound b) has it the other way around, then the main (1s - 4p) absorption peak in compound a) will be smaller than in b) after edge ste

Re: [Ifeffit] Fit XANES spectra using Athena

PCA works only if there are series of spectra with change in the makeup of S species, not for a single spectrum. Anatoly - Original Message - From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> To: ifeffit@millenia.cars.aps.anl.gov Sent: Sun Oct 26 13:05:32 2008 Subject: Re: [Ifeffit] Fit XAN

Re: [Ifeffit] Ifeffit Digest, Vol 67, Issue 11

No, if you enter any number in the energy shift window, the entire scale is shifted. This linear scaling can be done only for small shifts, in XANES region. For larger shifts you need parabolic correction, or even use a splice method where different corrections are applied to different sub-ra

Re: [Ifeffit] Comparison of "amp" between Feff8.40 and feff6 - Curved waves or Plane waves?

By looking at the FEFF.inp file it appears that the path in question is a Ti-O-Ti where the angle of this linkage is very close to 180 degree (had it been 180 degree, the total length would be not 3.9317 but either 3.90500 or 4.15600. In a perovskite with Ti on center such angle would be 180 deg

Re: [Ifeffit] questions concerning paper

We should ask John Rehr to rename FEFF to Odysseus. It makes both physical and mythological sense. Anatoly - Original Message - From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> To: Ravel, Bruce; XAFS Analysis using Ifeffit Sent: Thu May 22 14:30:38 2008 Subject: Re: [Ifeffit] questions c

Re: [Ifeffit] Using the amplitude reduction factor as alinearcombination fitting parameter

An option could be, if you collected just one spectrum, to construct 1st shell EXAFS data for each compound using FEFF and use a linear combination option of Athena to see if there is any value of the mixing fraction of these two theoretical compounds that resemble good fit. You will still need

Re: [Ifeffit] Using the amplitude reduction factor as a linearcombination fitting parameter

There are a few points in your description that puzzle me. Have you collected not one but a series of spectra where some external condition (e.g., temperature, concentration, time, pH etc) were varied? If not, PCA cannot be used if only one spectrum was collected containing a mixture of two spec

Re: [Ifeffit] cofe2o4 chi data

I have it. Anatoly -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Tai-Yen Chen Sent: Monday, January 14, 2008 12:27 PM To: XAFS Analysis using Ifeffit Subject: [Ifeffit] cofe2o4 chi data Dear all Does anyone have cofe2o4 chi data by anychance or know

Re: [Ifeffit] Log-Ratio

It adds (or subtracts) 2pi to the phase difference between the unkown and the standard as some times it does not eztrapolate to zero as 2k*delta r term should. Anatoly -Original Message- From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> To: ifeffit@millenia.cars.aps.anl.gov Sent: Wed Dec

Re: [Ifeffit] Exafs distance resolution

Yes and a very important one - see Ed Stern's talk at the 2001 EXAFS workshop "advanced methods and tricks etc. " His talk is online. Anatoly -Original Message- From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> To: ifeffit@millenia.cars.aps.anl.gov Sent: Tue Nov 27 04:44:48 2007 Subject: [

Re: [Ifeffit] Farrel-Lytle database query

It makes sense. An easy check would be to compare EXAFS of samples 13 and 14. If 13 was taken at lower temperature than 14 it will be shown by higher EXAFS oscillation intensity Anatoly -Original Message- From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> To: Andy Higginbotham <[EMAIL PROTECT

Re: [Ifeffit] Debye Waller factors for Water Molecules

Paul, In addition to my previous email, before you decide whether to set and fix the Zn-O DWF or not, I suggest that you look for a spread in reported values of DWF in Zn2+ -O in aqueous solutions - most of them were done at room temperature, but to get an idea about the spread it only matters

Re: [Ifeffit] Debye Waller factors for Water Molecules

Paul and Shelly, I do not think Einstein temperature for Zn-S bond should be recycled as the Einstein temperature for a Zn-O bond. To my opinion, the best approximation for Zn-O Einstein temperature would be to look up for EXAFS data on Zn2+ complexes in aqueous solution, assume that what they

[Ifeffit] Cluster coordinate generator

Hi all: The first version of the Cluster geometry generator is available on the web: http://www.yu.edu/scc/index_sub.asp?id=2711 (follow the second link under Software) The programs from this package will generate cartesian coordinates of regular polyhedra - those which are most popular in n

Re: [Ifeffit] [howto] configurational average in EXAFS with FEFF

Mauro, If I do understand your question correctly, you may be asking how to handle a multiple of inequivalent sites in atomic clusters with N atoms, where each atom generates a unique sequence of single- and multiple-scattering paths. A possible solution is given in this article: D. Glasner

Re: [Ifeffit] EXAFS reference materials

Thanks, Scott! - Good point. A. From: [EMAIL PROTECTED] on behalf of Scott Calvin Sent: Thu 3/22/2007 3:48 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] EXAFS reference materials Hi Ruoshuang, Following up on Anatoly's excellent post, I would say t

Re: [Ifeffit] EXAFS reference materials

Hope it helps, Anatoly From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thu 3/22/2007 2:54 PM To: Frenkel, Anatoly Subject: EXAFS reference materials Dear Dr. Frenkel, I'll do EXAFS on metallic glass but I am not sure about the reference materials.

Re: [Ifeffit] E0 for bulk crystals and nanoparticles

That's true - if there are no "shift-like" changes in XANES, E0 may be constrained. Anatoly From: [EMAIL PROTECTED] on behalf of Scott Calvin Sent: Sun 2/25/2007 10:20 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] E0 for bulk crystals and nanopartic

Re: [Ifeffit] E0 for bulk crystals and nanoparticles

Leandro - depending on the details of your system and treatment, electronic structure of the nanoparticle may or may not change at elevated temperatures. It may change as a result of hydrogen chemisorption, charge exchange with support, ligand desorption, oxidation, etc. As a result, you may obs

[Ifeffit] Postdoc search

Dear IFEFFIT users: please announce it to those who may be interested in this position. Thank you, Anatoly Postdoctoral position at Yeshiva University and the National Synchrotron Light Source Physics Department of Yeshiva University in New York City has immediate opening for a postd

RE: [Ifeffit] Alloy EXAFS data fitting

resending, now typing more carefully: *** Hey Xianqin, If it is a (bulk) alloy system, and if A-A and A-B are 1NN pairs, then, unless there is a phase transition or other perturbations that can involve chemical changes either within the sample of heterogeneous (say, nanophase formation of diff

RE: [Ifeffit] Alloy EXAFS data fitting

Hey Xianqin, If it is a (bulk) alloy system, and if A-A and A-B are 1NN pairs, then, unless there is a phase transition or other perturbations that can involve chemical changes either within the sample of heterogeneous (say, nanophase formation of different composition) or homogeneous (say, ord

RE: [Ifeffit] Right way of choosing E0 in Athena

Vadim, The ss2 of multiple-scattering (ms) paths and single-scattering (ss) paths are not simply related unless the legs in the ms paths are collinear. In that case, as published in Frenkel, Stern, Qian, Newville, Phys. Rev. B, 48, 12449 (1993), if the intervening atom is a first nearest nei