Jatin, Estimating the size from EXAFS data alone may be very risky because you will have to assume a certain shape and morphology (say, 3D such as cuboctahedral, or oblate, such as truncated cuboctahedral) in order to find the size from EXAFS coordination numbers. They CNs are "indices" that describe not just size but the entire architecture, and there may be more than one such architecture that fits those four indices. The simplest architectures that you can consider for modeling purposes are closed shell clusters that can be constructed from a seed cluster of a given shape by adding more layers on it until your model CNs and experimental CNs match within the error bars. However, such analysis is predicated that you have excellent size and shape selectivity. Hence, you need an independent data such as TEM, to get statistical information about the size/shape distribution. Of course, you need to make synthesis also size-shape selective as well. If you do not have good control over size/shape, your analysis using 4 shells is an overkill. You can get average size by estimating it using Scott Calvin's equation in J. Appl. Phys. 94:778–83. If you do have a good control over size/shape you should first question your fitting process that gives you the CNs and their uncertainties. You have to check if you included the most important multiple scattering contributions, the stability of the fit results to the changes in your fitting scheme (e.g., the ways you constrain (or not) parameters of single and multiple scattering collinear paths). You may also decide to check your model on bulk Cu and see if you will obtain correct CNs if you vary them (by fixing the S02). If you find that the CNs in bulk Cu are not in agreement with the crystallography, you should not expect anything meaningful from the CNs in your nanoparticle if you obtain them using the same fitting scheme as for the bulk. After all the above is done, then you can do some modeling using CNs from 1st through 4th shell. Here are some references how to do that using EXAFS results: J. Phys. Chem. B, 105, 12689-12703 (2001). J. Synchrotron Rad., 6 , 293 (1999). Zeitschrift fur Kristallographie, 222, 605-611 (2007). Ann. Rev. Anal. Chem., 4, 23-39 (2011) J. Am. Chem. Soc. 132, 8747-8756 (2010) Anatoly ________________________________________ From: ifeffit-bounces@millenia.cars.aps.anl.gov [ifeffit-bounces@millenia.cars.aps.anl.gov] on behalf of Rana, Jatinkumar Kantilal [jatinkumar.rana@helmholtz-berlin.de] Sent: Thursday, January 09, 2014 12:55 PM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] correlating number of nearest neighborst to the particle size Hi All, I would like to estimate the size of Cu nanoparticles grown in my sample by EXAFS fitting. I can refine the number of nearest neighbors in these Cu nanoparticles up to 4 shells (say NN1, NN2, NN3 and NN4), by constraining S02 to the value obtained by fitting the data of Cu reference foil. But, how do I correlate the refined values of nearest neighbors to the actual size of Cu nanoparticles ? Any help in this regard would be much appreciated. Regards, Jatin -----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of ifeffit-request@millenia.cars.aps.anl.gov Sent: 09 January, 2014 17:51 To: ifeffit@millenia.cars.aps.anl.gov Subject: Ifeffit Digest, Vol 131, Issue 8 Send Ifeffit mailing list submissions to ifeffit@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@millenia.cars.aps.anl.gov You can reach the person managing the list at ifeffit-owner@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. Query re: Athena and Artemis user guides (Leon Clarke) 2. Re: Query re: Athena and Artemis user guides (Bruce Ravel) 3. Re: Query re: Athena and Artemis user guides (Kathy Dardenne) 4. Re: Demeter 0.9.19 (Schima, Frank) ---------------------------------------------------------------------- Message: 1 Date: Thu, 9 Jan 2014 15:56:29 +0000 From: Leon Clarke To: "ifeffit@millenia.cars.aps.anl.gov" Subject: [Ifeffit] Query re: Athena and Artemis user guides Message-ID: <83CF3E8AA2102C4598B316168B472EFE98BEEECD@drmb1> Content-Type: text/plain; charset="us-ascii" Dear Dr Ravel and Demeter users, I recollect that the Athena and Artemis user guides used to be available as PDF files (which I found useful). Am I correct that the latest guides are now only accessible as internet pages, as I can't seem to find a download link? Best regards, Leon ----- Dr Leon J. Clarke Lecturer in Environmental Analytical Chemistry Division of Chemistry and Environmental Sciences School of Science and the Environment Faculty of Science and Engineering Manchester Metropolitan University John Dalton East Oxford Road Manchester M1 5GD E-mail: l.clarke@mmu.ac.ukmailto:l.clarke@mmu.ac.uk WWW: http://www.sste.mmu.ac.uk/ Tel: +44 (0)161 247 1412 "Before acting on this email or opening any attachments you should read the Manchester Metropolitan University email disclaimer available on its website http://www.mmu.ac.uk/emaildisclaimer "