[Ifeffit] Negative ss problem

[Abhijeet Gaur]

Hi all,
          I read the discussion on negative Debye waller factor. As per the
discussion the negative value of this factor shows that the model has
shortcomings, so it should be corrected.
         I am also getting the same problem while fitting one of my samples.
It is a Cu complex whose EXAFS data is taken at Dispersive EXAFS beamline at
RRCAT, Indore, India.
        In the complex the nearest neighbours of Copper atom are Nitrogen
and Oxygen.
        I am getting a very good fit upto 3rd shell but the problem is that
all ss parameters are coming negative. I checked the model it seem correct.
        Also I am getting a peak below 1 Angs which is also getting fitted
but I am not able to get that whether it is a real or due to some noise.
        I am attaching herewith the results of data analysis and fitting.
        Thanks in advance
        With regards
     Abhijeet Gaur
Vikram University
Ujjain, INDIA
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