Hi, I would like to apply a rotation to a pdb model, in order to place copies of it in equivalent symmetry points (icosahedral symmetry). I am not sure I understand all the different coordinate systems in chimera, but digging into the program code, I was able to write the following script. I am not sure it is the best way to do it, and obviously at the moment it does not work properly, because I am not specifying the center of rotation. With respect to the coordinates of the pdb model, I know the center of symmetry, let's say (161,161,161), but I don't know how to impose it. I tried to assign these coordinates to the parameter 'cofr', but the result does not change. Does anyone know how to apply, inside a script, a rotation matrix around a given point? Any other feedback on the correctness of the script is very welcome. Thank you. Giovanni ############################################### from chimera import openModels, Point from PDBmatrices import chimera_xform from Icosahedron import icosahedral_symmetry_matrices icomats = icosahedral_symmetry_matrices(orientation = '222r') for rmat in icomats: xf = chimera_xform(rmat) m, = openModels.open('/dummy/dummy.pdb') # open a copy of the model m.openState.xform = xf # set rotation ############################################### ============================================= Giovanni Cardone Laboratory of Structural Biology Research National Institutes of Health 50 South Drive (Building 50), Room 1511 Bethesda, MD 20892-8025 USA Tel: (301) 451-8247 FAX: (301) 480-7629 Giovanni_Cardone@nih.gov =============================================