[Chimera-users] view along a crystal axis

[Elaine Meng]

Hi Michael,
I can't think of a direct way to align the view on a crystallographic axis... there is an "align" command to exactly align specified atoms along the line of sight in the center of the window:

<https://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/align.html>

However, there may not be atoms that lie exactly along or parallel to the crystallographic axis, or it may not be easy to identify them.  

One roundabout way might be to use the Crystal Contacts tool (in menu under Tools... Higher-Order Structure) and click "Show Contacts" which shows the outline as markers and links.  Markers are essentially fake atoms, so you could select the two corners of the outline box you want to align (Ctrl-click, Shift-Ctrl-click) and then use command "align sel" ... then hide or delete the markers and links after you get the desired alignment.

<https://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/crystalcontacts/crystalcontacts.html>

You might not want that in the center of the window, however, so additional translation ("move" commands) may be required afterwards.
<https://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/move.html>

I couldn't do the "atom" selection with the box shown by Unit Cell because I think it is just a mesh and the whole box gets selected instead of corners.

Other related commands...

Command "reset" will give coordinate Z axis along the line of sight.

Command "set projection orthographic" may be helpful to turn off perspective.

Since the alignment is somewhat of a rigamarole, you may prefer to keep doing it your current way!

I hope this helps,
Elaine
-----
Elaine C. Meng, Ph.D.                       
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco




> On Jan 8, 2021, at 6:09 AM, Michael Elbaum <michael.elbaum at weizmann.ac.il> wrote:
> 
> Hi.   I would like to view a lattice of molecules generated by "Unit Cell" along a given axis. Is there a way to set the view accordingly, say along a, b, or c axis? Other than showing the I'm showing the outline box and eye-balling, but probably there's a more precise way to do this.
> thanks for your help,
> Michael
> _______________________________________________
> Chimera-users mailing list: Chimera-users at cgl.ucsf.edu
> Manage subscription: https://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users