Hi all, I was trying to solve the structure of a protein in several different datasets using xds and phenix. I could solve the structure from one dataset in space group P4. For another dataset, I could solve the structure using the monomer of the structure I got from the first dataset as search model and solve the structure in space group mC. For the third dataset, in IDXREF.LP, the space group of the highest symmetry is hp: 101.2, 101.3, 58.8, 90, 90, 120. According to Mathiews coefficient, 1 monomer is expected in the asymmetric unit. But I couldn't get the molecular replacement solution using the same method as for the second dataset. I also tried several other search models (eg. deletion of the potential flexible region in the search model) and tried to find the solution in all possible pointgroup. I also tried to process the data in oC (C222), the space group of the second highest symmetry in IDXREF.LP, but, still I could not get right molecular replacement solution. I don't whether this means that there is a big conformational change for the structure in the third dataset or the space group I use is not right. Let me know if any of you would have any comments or suggestions for me. Thank you so much! Best, Wei