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    Hi Carlos,<br>
    <br>
    Please clarify somethings for me regarding your inquiry.<br>
    You have a structural model and you have data.<br>
    You calculated a FEFF simulation of your structural model.<br>
    You did not use the FEFFNNNN.dat files to try to fit the model to
    your data,<br>
    but instead just did a comparison of the simulated chi(k),
    presumably<br>
    with just some default settings in FEFF.inp in addition to your
    structural model.<br>
    Is that correct?<br>
    <br>
    Generally, it is the fit to the data that gives one feedback on the
    validity<br>
    of the structural model (GIGO rules apply). <br>
    <br>
    If you have a model, then you have a model coordination number and
    can use <br>
    a program (e.g. Artemis) to refine amplitude, distance,
    mean-square-relative displacement<br>
    and energy shift. Do you need explanations of what these parameters
    represent?<br>
    <br>
    So, to address what you were wondering, I believe the answer is
    yes...you need to actually<br>
    do a fit, and the goal isn't to get the obtained spectrum to look
    like your simulation.<br>
    Data is sacred. The goal is find a model that best reproduces the
    data (within a confidence<br>
    level governed by the goodness of fit).<br>
    <br>
    regards,<br>
    Robert<br>
    <br>
    <div class="moz-cite-prefix">On 11/5/2015 7:06 AM, Carlos Triana
      Estupinan wrote:<br>
    </div>
    <blockquote
cite="mid:CAGrEcD8pC1dgOFQCkCOhvKcnHcVEw_B96jdqBgDbT=q68o_ZMQ@mail.gmail.com"
      type="cite">
      <div dir="ltr">Dear 
        <div>Bruce</div>
        <div><br>
        </div>
        <div>I am doing calculation of EXFAS for a amorphous structure
          created by molecular dynamics. I am using FEFE to obtain
          chi(k) and the file xmu, however, when comparing with
          experimental data with the calculated EXFAS I have the
          following problems.</div>
        <div><br>
        </div>
        <div>1) The Fourier transform of the EXAFS calculated by FEFF
          has the same shape that the experiment spectra, however it is
          higher in amplitude. </div>
        <div><br>
        </div>
        <div>2) The calculated EXFAS by FEFF has the same oscillation in
          K-space, but it does not match the oscillation in K (both of
          them are shifted to each other).</div>
        <div><br>
        </div>
        <div>I am wondering if I need to do an extra correction to the
          calculated EXAFS by FEFF in order to match the K-space and the
          amplitude in R-sapace. Shall I change the energy shift or the
          Edge step to match the experimental spectra. I so, how can I
          am sure about the obtained spectra really correspond to my
          molecular dynamics simulation.</div>
        <div><br>
        </div>
        <div>Thanks for your help.</div>
        <div><br>
        </div>
        <div>Regards.<img
            src="cid:part1.06070808.00000704@alumni.sfu.ca" height="243"
            width="370"><img
            src="cid:part2.08090501.01030308@alumni.sfu.ca" height="235"
            width="388"><br>
          ​<br>
        </div>
        <div><br>
        </div>
        <div><br>
        </div>
      </div>
      <div class="gmail_extra"><br>
        <div class="gmail_quote">2015-11-03 13:42 GMT+01:00 Bruce Ravel
          <span dir="ltr"><<a moz-do-not-send="true"
              href="mailto:bravel@bnl.gov" target="_blank">bravel@bnl.gov</a>></span>:<br>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">
            <div class="HOEnZb">
              <div class="h5">On 10/28/2015 08:44 PM, 百度知道用户 wrote:<br>
                <blockquote class="gmail_quote" style="margin:0 0 0
                  .8ex;border-left:1px #ccc solid;padding-left:1ex">
                  Hi all,<br>
                  I processed a series of data using IFEFFIT Athena, and
                  saved it as a<br>
                  project. Later, when I opened the project in IFEFFIT
                  Athena, the plot<br>
                  window did not show the curve. I tried to open the
                  project in Demeter<br>
                  Athena, but  popuped "Can't call method "datatype" on
                  an undefined<br>
                  value". The data curve was also not shown. I want to
                  know what happened<br>
                  to this? Are the data damaged? I am very thankful if
                  this problem can be<br>
                  solved.<br>
                </blockquote>
                <br>
              </div>
            </div>
            It is hard to address a problem like this without an
            actionable bug report.  See <a moz-do-not-send="true"
              href="http://bruceravel.github.io/demeter/pods/bugs.pod.html"
              rel="noreferrer" target="_blank">http://bruceravel.github.io/demeter/pods/bugs.pod.html</a><br>
            <br>
            B<br>
            <br>
            -- <br>
             Bruce Ravel  ------------------------------------ <a
              moz-do-not-send="true" href="mailto:bravel@bnl.gov"
              target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:bravel@bnl.gov">bravel@bnl.gov</a></a><br>
            <br>
             National Institute of Standards and Technology<br>
             Synchrotron Science Group at NSLS-II<br>
             Building 535A<br>
             Upton NY, 11973<br>
            <br>
             Homepage:    <a moz-do-not-send="true"
              href="http://bruceravel.github.io/home/" rel="noreferrer"
              target="_blank">http://bruceravel.github.io/home/</a><br>
             Software:    <a moz-do-not-send="true"
              href="https://github.com/bruceravel" rel="noreferrer"
              target="_blank">https://github.com/bruceravel</a><br>
             Demeter:     <a moz-do-not-send="true"
              href="http://bruceravel.github.io/demeter/"
              rel="noreferrer" target="_blank">http://bruceravel.github.io/demeter/</a><br>
            _______________________________________________<br>
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          </blockquote>
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        <br>
        <br clear="all">
        <div><br>
        </div>
        -- <br>
        <div class="gmail_signature">
          <div dir="ltr">
            <p><i><span style="font-family:"Times New Roman""
                  lang="ES-TRAD">Carlos Augusto Triana Estupiñan
                  (C.A. Triana-E)<br>
                  Physicist<br>
                  M.Sc. In Physical Sciences-Research<br>
                  PhD Student-Research <br>
                  Ångströmlaboratoriet, Lägerhyddsv. 1<br>
                  Solid State physics<br>
                  Uppsala University, Box 534<br>
                  751 21 Uppsala, Sweden<br>
                  Tel: +46 018 471 3144<br>
                  <a moz-do-not-send="true"
                    href="mailto:e-mail%3Acarlos.triana@angstrom.uu.se"
                    target="_blank">e-mail:carlos.triana@angstrom.uu.se</a><br>
                  web:<a moz-do-not-send="true" href="http://www.uu.se/"
                    target="_blank">http://www.uu.se/</a></span></i><span
                style="font-family:"Times New Roman""
                lang="ES-TRAD"></span></p>
            <i><span style="font-size:10.0pt;font-family:"Times New
                Roman"" lang="EN-US"></span></i>
            <i><span style="font-size:10.0pt;font-family:"Times New
                Roman";color:#1a1a1a" lang="EN-US"></span></i></div>
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