Hello Alexandra, <br>I believe you have to reprocess the data keeping friedel pairs (f+ and f- ) separate to make use of the little most anomalous signal (if any) at your collected wavelength. The best thing would be to collect a high redundant set of peak data (if not all the three data sets including mad remote and inflection data) If you have access to a tunable source and xtals left. Once you process differently, you can do all sorts of substructure search and later refine anomalous scatterers using wavelength, atom type and f ' and f“ values. Sulphur sad is also a good possibility if you have a decent nmbr of sulphurs in your protein.<br><br>Hope this suffices your query.<br><br>Regards<br>Ashok Nayak<br>CSIR CDRI,<br>Lucknow, India<br><br>Alexandra Marques <at.marques@fct.unl.pt> wrote:<br><br><div dir="ltr">
<p class="MsoNormal">Hi,</p><p class="MsoNormal"><br></p>
<p class="MsoNormal">I am in the last refinement steps of a MR model and I want
to calculate an anomalous difference map<span style>
</span>essentially to confirm the presence of a sulfite molecule and to locate vanadium
(present in soaking solution). I read that it is necessary to have a mtz file
with anomalous data (i.e. F+,F- or I+,I-). However, my data was collected at “normal”
wavelenght (0.97) and it was processed with XDS considering Friedls law= true
and my mtz file contain the following columns: H K L FP SIGFP. So, can I still
calculate a anomalous difference map based on my data?</p><p class="MsoNormal"><br> </p>
<p class="MsoNormal">Since I also have a Mo atom in the active site can I try to
refine its occupancy by using the option “anomalous groups” in the refinement
strategy? <br></p><p class="MsoNormal"><br></p>
<p class="MsoNormal">Thank you very much, </p>
<span style="font-size:11pt;line-height:115%;font-family:"Calibri","sans-serif"">Alexandra</span></div>