Re: [Ifeffit] (no subject)

2007-11-27 Thread Bruce Ravel
On Tuesday 27 November 2007 09:12:33 Bindu R. wrote: could you tell me how does one tune the bond angles from the multiple scattreing paths? Hi Bindu, I don't quite understand the question. Perhaps you can offer a few more details about what you are trying to do Are you doing EXAFS

Re: [Ifeffit] (no subject)

2007-11-27 Thread Carlo Segre
Hi Bindu: I am presuming that you mean that you want to tune the bond angle of the MS paths in your EXAFS fitting but, as Bruce notes, I might be wrong. The bond angles for the multiple scattering paths are simply calculated from the positions of the atoms around the central atom in the FEFF

[Ifeffit] Exafs distance resolution

2007-11-27 Thread Eric Breynaert
Dear all, Is there a physical limitation determining exafs bond distance resolution? Very often the equation r = pi / 2 deltak is quoted as a measure for bond distance resolution. But as i understand this equation is related to the fourier transform traditionally used for exafs analysis. If

[Ifeffit] (no subject)

2007-11-27 Thread Bindu R.
could you tell me how does one tune the bond angles from the multiple scattreing paths? Bindu Dr.Bindu R. Visiting Scientist DCMPMS Tata Institute of Fundamental Research Homi Bhabha Road Colaba Mumbai-400 005 India Mobile-919892536830 - Chat on a cool,

Re: [Ifeffit] Exafs distance resolution

2007-11-27 Thread Frenkel, Anatoly
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 ifeffit@millenia.cars.aps.anl.gov Sent: Tue

Re: [Ifeffit] Exafs distance resolution

2007-11-27 Thread Kropf, Arthur Jeremy
This question comes down to the following practical problem. If one has a theoretical model developed using computational chemistry that predicts two different bond lengths within one shell, e.g. an octahedral metal center surrounded by 6 oxygen atoms and this shell is predicted

Re: [Ifeffit] Exafs distance resolution

2007-11-27 Thread Bruce Ravel
On Tuesday 27 November 2007 12:02:57 Kropf, Arthur Jeremy wrote: My guess would be that the EXAFS could probably be fitted just as well with one distance and a slightly larger sigma2 as with 3 separate distances. But this would depend some on the data quality and it might be right at the

Re: [Ifeffit] (no subject)

2007-11-27 Thread Bruce Ravel
On Tuesday 27 November 2007 09:33:20 Carlo Segre wrote: The bond angles for the multiple scattering paths are simply calculated from the positions of the atoms around the central atom in the FEFF input file.  In the refinement process used by Ifeffit, the overall path length is slightly