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Dear All, Recently, I collected a dataset of a protein-DNA complex and indexed in spacegroup P212121 to 3.4 Å. However, Phenix.Xtriage indicated the presence of a very high pseudotranslational symmetry peak. I scaled the data in spacegroup P222. When I used the protein heterotetramer as search model to do the MR, solutions are suggested in P22121, P212121, P2212, P21212 and all with a TFZ score higher than 15, LLG higher than 570. Then I used phenix.refine to refine those solutions; however the Rfree is as high as 0.54-0.56. The refinement strategy that I used for the refinement is rigid body, group B-factors and XYZ coordinates. How to deal with this pseudotranslational symmetry problem? Does a solution with such high TFZ scores mean that the correct one has been found? How to solve the spacegroup problem in such situation? Do you have any suggestions? Thank you very much. Greetings, Yurong