Hi Ben, If you Ctrl-doubleclick a bond, a menu should show up that includes the option to "Set Bond Length" - this opens a dialog in which you can change the length. Another route to the same thing is to open the "Build Structure" tool (under Tools... Structure Editing), change to the "Set Bond Length" tab, Ctrl-click on a bond to select it, and edit the length in the dialog. I just now tested this in 1.2470, the production release from last November, with structure 1zik fetched from the PDB. I am guessing you really have this version (1.1470 would be astoundingly old, and I'm not sure we ever made a release with that version number). Even though you can change bond length in 1.2470, I recommend getting the newer production release 1.2540 for its many new features and improvements: http://www.cgl.ucsf.edu/chimera/download.html#production I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng@cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html On Jul 11, 2008, at 12:13 AM, Benjamin G.S. Horsman wrote:

Hello,

I have what appears to be simple problem but is I can't find the solution in previous mailing list queries. My problem is that I am unable to modify the lengths of any bonds in a PDB molecule. I am rather frustrated with myself over such a stupid problem, having tried dozens of times over dozens molecules to get it right but to no avail. Any possible solutions from the community? I am using MacpyMol to generate PDB structures and Chimera v1 build 1470.

Thanks for any help,

Ben