Hi doctor, when I open a map (ID 1) and a model (ID 2), the map is the whole icosahedron while the model is the protomer of the icosahedron. I want to apply symmetry I to generate an icosahedron model. I have rotated and translated the model into a reasonable position inside the map and then done a “fit in map” to get the initial placement for sym. Then I enter a command ''measure center #1''，center of mass xyz coordinates for map_sharp.mrc = (238.08, 238.08, 238.08)，enter another command ''sym #2 I,222 center 238.08, 238.08, 238.08'' I can see an icosahedron model fit in map. But when I save the icosahedron model.pdb, I found the icosahedron model actually is the model of the protomer. How can I apply symmetry I to generate a true icosahedron model, used for subsequent model refine in coot and real_space_refine in Phenix. Thank you very much. Best wishes! yanting 延婷 yanting.tang@mail.nankai.edu.cn