Hi Ajith, The union symbol is a vertical bar. So if you had a named selection named light and another named heavy, to display both you could use disp light | heavy That also works without the spaces on either side of the vertical bar, and you can use the same approach in all kinds of commands (color, ribbon, etc.) not just display. <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/atom_spec.html#combinations> You might want to take a look at aliases rather than named selections. With aliases you don't have to go through selection, you just name the set of atoms directly. However, if you are generating the selection anyway by some process (say findclash), namesel may still be more convenient. <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/alias.html> <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/namesel.html> Probably many people start using named selections because that is the terminology in Pymol, whereas in Chimera, an alias is usually more convenient. I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Jun 1, 2010, at 3:06 PM, Ajith Harish wrote:

I have a model with multiple proteins. Each protein chain is split into a separate pdb file (and so separate model). I have selected domains of some proteins or complete chains or others and assigned names to them from the 'namesel' command.

I am unable to select multiple named selections at a time to hide certain selections. Could you please let me know how to hide/show groups of named selections.

Thank you, Ajith