Thanks Bruce. Indeed having the real equation that Artemis is manipulating would be great for recent version too. I am a bit surprised about φc and φeff. I was expecting radian unit... Best Regards, Samy Ould-Chikh KAUST Catalysis Center Bldg.3,Level 4, #4231 4700 King Abdullah University of Science & Technology Thuwal 23955-6900 Kingdom of Saudi Arabia Tel: +966 12 8084486 E-mail: samy.ouldchikh@kaust.edu.sa Website: http://kcc.kaust.edu.sa/Pages/Home.aspx -----Original Message----- From: Ifeffit [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of Bruce Ravel Sent: Tuesday, February 28, 2017 6:48 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Units for various parameters of ‘feffNNNN.dat’ file On 02/28/2017 10:10 AM, Samy Ould-Chikh wrote:

Dear Ifeffit mailing list,

I have a question which concern units and I can’t find the answer in the Feff manual.

In a FeffNNN.dat output file, what are the unit of the numbers (if any) corresponding to

φc,

|Feff|,

φeff,

the reduction factor,

λ,

Re(p)

Samy, This is a peculiar reference, but I think the clearest written explanation of this is in the manual for the ancient "feffit" program. Here is a copy of its manual: http://cars.uchicago.edu/~newville/feffit/feffit.pdf You will want to look at page 22. While the rest of the manual is not so useful anymore (in the sense that there are very few users of the old feffit remaining), it's explanation of how the feffNNNN.dat files are used is excellent. Eq. 6.1 should clarify how each term is used and what the units are. Column 1 is, of course, inverse Angstroms. Columns 2, 3, and 4 are unitless. The two phase terms go into the argument of the sine, thus must be unitless. The amplitude term is multiplied by N and S02, thus is also unitless. The reduction factor, as well, is unitless -- it is used in the computation of the amplitude term in equation 6.1. Lambda has units of angstroms, the real part of p (which is the complex wavenumber used in the Feff calculation) has units of inverse Angstrom. I am pretty certain I got all that right. I think it would be a good idea to capture all of this information as well as eq. 6.1 in the Artemis manual. HTH, B -- Bruce Ravel ------------------------------------ bravel@bnl.gov National Institute of Standards and Technology Synchrotron Science Group at NSLS-II Building 743, Room 114 Upton NY, 11973 Homepage: http://bruceravel.github.io/home/ Software: https://github.com/bruceravel Demeter: http://bruceravel.github.io/demeter/ _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit ________________________________ This message and its contents including attachments are intended solely for the original recipient. If you are not the intended recipient or have received this message in error, please notify me immediately and delete this message from your computer system. Any unauthorized use or distribution is prohibited. Please consider the environment before printing this email.