Dear Jules, Sorry, there is no option to show double bonds with two lines, although we have recently added (version 1.4) the ability to show aromatic rings with circles or disks: <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/aromatic.html> Best, 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 Nov 24, 2009, at 3:35 AM, J H wrote:

Dear Chimera, Is there a way to display a molecule's double bond as double-bond (i.e., two lines between the atoms instead of one) in chimera? Thanks a lot. Best,