I don't understand what you are trying to do. My best guess is you have a symmetric trimer crystal structure and you want to fit a monomer of that atomic model into a 5-fold symmetric map. To do that I would open the trimer atomic model, delete all except one monomer, fit it into one of the 5 equivalent positions in the map, then use the "sym" command to make the other 4 symmetrically placed copies. If I wanted to reduce clashes I'd assign c5 symmetry to the map as described before and use the "fitmap" command with the symmetric fitting option. The "volume #0 symmetry c5" command doesn't give any error message like "can't find symmetry". So I'm not sure what problem you are having. You need to explain it more clearly. Tom

Tanks for your kindly answer!But i use the command volume #0 symmetry c5,it tell me that cann't find the semmetry. The map is made from crystal structure using "fit in map".it a trimer,i want to impose 5-symmetry in order to fit with my map.

At 2013-04-17 05:43:04,"Tom Goddard" <goddard@sonic.net> wrote:

How about the Chimera command

volume #0 symmetry c5

The symmetry assigned to the map isn't used for much in Chimera. It can be used for symmetric fitting but if you tell it the wrong symmetry you will just get nonsense fits. The other main use of symmetry is to replicate PDB models with the sym command. There you can specify the symmetry with command options. So I can't think of any reason you would use the above command.

http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/sym.html

http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/volume.html#dimensions

Tom

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Dear sir I have some question in using your excellent Chimera. How can i set 5 symmetry to a 3 symmetry map? thank you