Possible bug in fitting
Hello IFEFFIT users, I am working on LiNi0.5Mn1.5O4 cathode materials, I am pretty sure that some of you already worked on it. On the first look, a multiple edge analysis on both Ni and Mn is interesting; however it’s not that straight forward due to multiple phase and oxidation states. I started doing multiple edge fit, but I gave up briefly. Then I did individual edge analysis and obtained some values. Looking at both edges my Ni fit looks good. So I thought of taking the Ni-Mn bond distance as well as DW factor value to Mn edge and set this value for my Mn-Ni paths. However it seems like this value is further evaluated in the fit and giving a new value. Can someone reproduce this, please see the project file and the Log file attached, Is it a possible bug or am I doing something wrong? Thank you, Ditty -- Ditty Dixon, Anorganische Chemie Karlsruhe Institute of Technology Kaiserstr 12 Karlsruhe, Germany Ph no: 004972160848093
Hi Ditty,
On Wed, Apr 30, 2014 at 7:05 AM, Ditty Dixon
Hello IFEFFIT users,
I am working on LiNi0.5Mn1.5O4 cathode materials, I am pretty sure that some of you already worked on it. On the first look, a multiple edge analysis on both Ni and Mn is interesting; however it’s not that straight forward due to multiple phase and oxidation states. I started doing multiple edge fit, but I gave up briefly. Then I did individual edge analysis and obtained some values. Looking at both edges my Ni fit looks good. So I thought of taking the Ni-Mn bond distance as well as DW factor value to Mn edge and set this value for my Mn-Ni paths. However it seems like this value is further evaluated in the fit and giving a new value. Can someone reproduce this, please see the project file and the Log file attached, Is it a possible bug or am I doing something wrong?
To me, it looks like you've set the Mn-Ni distance and sigma2, and these values are used and reported as you set them. You probably meant to set Delta_R for the Mn-Ni path, or use "RMn-Ni - reff" for the Delta_R parameter for the Mn-Ni path. As it is, you told it to use ~2.92 Ang as Delta_R for the Mn-Ni path, which will get added to the starting distance. --Matt
participants (2)
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Ditty Dixon
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Matt Newville