Any crystal can be worked at as P1. What you know is that your crystal is not p212121
It can be P21212 P21221 P22121 P1121 P1211 P2111 P112 P121 P211 P1 And then there is twinning ... Suggestions: Use Pointless or Phenix.xtriage, feeding the unmerged p1 data to decide. Use the Zanuda server with the P212121 data to see if any sub-space group is best. Use a molecular replacement program with the option to test all space groups. A. Sent from my iPad On 19 Jan 2012, at 13:06, 조기준 <c-a...@korea.ac.kr> wrote: > Dear all, > > I have a data, and it has R/Rfree problem. > The data could be processed as P212121 and P1. > The resolution was 2.9, and unit cell parameters were a=73.527, b=90.035, > c=237.980, α=β=μ=90 and a=73.709, b=90.099, c=238.172, α=89.939, β=89.945, > μ=89.993 for P212121 and P1, respectively. > R/Rfree was 22.3/29.4 for P1 after several refinements. > However, I couldn’t decrease R/Rfree below 30.0/37.6 for P212121. > There were almost no differences on monomer structure and crystal packing > between P212121 and P1 after MR, and the electron densities followed trace of > peptide chain well. > Can anybody suggest me about this problem? > > Thank you. > Ki Joon Cho > >
