Hi Rocco, Sorry, Chimera does not have an option to show double bonds as two lines. There is only a related option for aromatic rings, see command "aromatic": <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/aromatic.html> 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 Feb 22, 2011, at 11:28 AM, Rocco Varela wrote:

How do I display double-bonds of small molecules in Chimera?