Hi Elaine,
Thank you so much for the help. I look up the original post answered by Tom, as he pointed out, "The tricky part will be to assign the correct center of symmetry and icosahedron orientation for the asymmetric piece using the origin and symmetry options of the volume command". He is very right and I could not figured out the way to assign the correct center of the symmetry and icosahedron orientation for asymmetric piece with volume command while I am using "cop cover". The map I tried is EMD-5199 (rotavirus). Could you please help me out?
Thanks again,
Zongli