We need more information. First if the pointgroup is hexagonal are you searching al likely SPACEgroup - eg PG P6, SGs might P6 P61 P62P63 P64 P65..
There is a GUI option to do this for both MOLREP & Phaser. You can guess the likely no of molecules using matthews In the GUI - that is in the MOL REp task - option analyse. Eleanor On 29 April 2014 10:21, Dom Bellini <dom.bell...@diamond.ac.uk> wrote: > Dear Sudarshan, > > I have the feeling the your R factor after Molrep is really high because > the program has failed to produce a correct/not-partial solution, which > could be due to many things, but usually the main problem is how good your > search model is. The difference in spacegroups is not a problem as in MR > the model will be rotated and translated inside the new cell. > > The number of molecules that you need to search for is a tricky question. > You need to make some educated guesses with help from analysis of, for > example, crystal solvent content (e.g., Matthews program from CCP4) and/or > self-rotation maps (Molrep or Polarrfn programs, also available from CCP4 > suite). > > If you have never before used molecular replacement, however, I would > advise that you get some help/guidance from some more experienced > colleague/friend in the Department, since you may encounter quite a few > more other problems that would perhaps be a bit too long to go through by > email. Some of these problems could also be probably self-solved by looking > at some tutorials on Molecular replacements. > > Best wishes, > > D > > > > > > > From: Sudarshan Murthy [mailto:sudarshan.murthy...@gmail.com] > Sent: 29 April 2014 05:11 > To: ccp4bb > Subject: [ccp4bb] Problem with Rfactor > > Dear All, > > I am very new to the field of crystallography, I have a few questions > which are very basic and getting input from this forum would help me a lot. > > Firstly I am trying to solve a structure using MR Molrep. In the result > the Rfactors are really high how do I reduce the same?? ..When I tried with > Phaser I didnt get any solution at all.. Will der be a problem with the > space group?? like the model is in monoclinic and the data which I have is > processed in hexagonal. > > Secondly while using hexagonal space group should I search for only one > monomer in Molrep?? > > These are very basic questions if anybody could help me out with this , I > would be very happy for the same. > > Sudarshan .N. Murthy > Crystallography Division > Bangalore >
