Hi Anna, Unfortunately it is a known bug in Tk (the windowing system used by Chimera) on Macs. Double-clicking anything does not work, sorry. There are alternative ways to accomplish the context menu actions. For example, looking at where doubleclicks are used in the the "Structure Analysis and Comparison tutorial": <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/tutorials/squalene.html> (1) For distance measurement, you can select two atoms (Ctrl-click one atom to select, Shift-Ctrl-click the second atom so that exactly two atoms are selected) and then: (A) use command: distance sel - OR - (B) menu: Tools... Structure Analysis... Distances, and in that tool click the "Create" button <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/structuremeas/structuremeas.html#distances> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/distance.html> (2) For rotating a bond, select the two atoms as above (in this case the atoms on either end of the bond), choose menu: Tools... Structure Editing... Adjust Torsions, and proceed using that tool as described in the tutorial. <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/editing/editing.html#adjust> (3) In the dialog to choose models to morph, doubleclicking would quickly add the model, but instead you can just singleclick the model and then click the "Add" button. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco

On Jul 20, 2020, at 4:10 PM, Anna V. Bachmann <anna.bachmann@centre.edu> wrote:

Hello,

I am a new user of chimera on MacBook Pro and have been working through the tutorials. In a few sections of the tutorials, it says to ctrl-doubleclick an atom/bond/etc. to get a context menu. I am able to ctrl-click to select as well as shift-ctrl-click to select additional items, but when I attempt to ctrl-doubleclick with my trackpad it behaves the same way as a ctrl-click. Because of this I’ve been unable to complete some of the tutorials. I have not been able to find a solution to this online or in the mouse preferences of chimera. Is there a setting I can change to allow double-clicking on chimera, or is there another way I can show the context menu? Thank you

Anna Bachmann