Hello all, I have just used phenix autosol and autobuild to phase and build an initial model of my structure with phase information from Tungsten (W), collected at the peak wavelength of 1.2134 Angstroms. Autosol works beautifully! I was able to perform W-SAD and get great maps, when I initially thought I would have to perform W-MAD! The problem I am having is during phenix.refine. When I run the refinement (with and without refining the group anomalous) and including my experimental phases, I see a giant negative peak in the Fo-Fc map at the location of my Tungsten. The rest of the map is beautiful. In the log file, I can tell that the scattering factor is high for tungsten (see below). I believe the negative density is telling me I have too many electrons present at the tungsten site. Can anyone help me figure out what I am doing wrong? I have attached my latest log file. ----------X-ray scattering dictionary---------- Number of scattering types: 7 Type Number sf(0) Gaussians W 1 73.70 2 Se 1 33.92 2 S 11 15.96 2 Mg 1 11.95 2 O 462 7.97 2 N 343 6.97 2 C 1326 5.97 2 sf(0) = scattering factor at diffraction angle 0. ========================== Anomalous scatterer groups ========================= Anomalous scatterer group: Selection: "name W" Number of selected scatterers: 1 f_prime: 16.87 f_double_prime: 17.72 refine: f_double_prime Total number of atoms in anomalous groups: 1 ******************************************************* Kelly Daughtry PhD Candidate Department of Physiology and Biophysics Boston University School of Medicine 590 Commonwealth Ave R 390 Boston MA, 02215 (P) 617-358-5548 *******************************************************