October 2018 - Chimera-users - RBVI Mailing Lists

Finding files my session is showing
by David Sáez 19 Oct '18

19 Oct '18

Hello everyone. I saved some sessions time ago. Now I found the .py files, and they work fine, but I do not remember what files I am opening when I restore the session. In the .py file I could not find any information about loaded topologies or pdb files. Can these data be recovered from a session? Thanks in advance

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Saving PDBs
by Elliott, Jabari 17 Oct '18

17 Oct '18

When attempting to save PDBs of multiple models into one file, I end up with a pdb file with no data (0-600 bytes). When attempting to open files in pymol, they are blank. Please advise. Thank you.

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Alias commands for volume pieces
by Benjamin Looker 17 Oct '18

17 Oct '18

Hello! I have recently received emails from Tom Goddard and Elaine Meng on this subject, but I believe it can be further clarified. The research group I am a part of routinely generates Gaussian cube files for molecular orbitals using the DFT program ORCA, we then manually use Chimera to change the level and color of the two phases of the resulting wave function, *which appear in Chimera as two **surface pieces* belonging to the same surface. In the volume viewer menu Data, *and* in the Model Panel, there is no way to see a #0.1 #0.2 model subnumber, and Group/Ungroup returns the error "Cannot group a single molecule." Is there a way to refer to volume pieces in the command line? Such that an alias can be written to do this formatting in a more efficient manner? Best, -- Benjamin G. Looker Graduate Student Lancaster Group

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Re: [Chimera-users] [chimera-dev] Chimera orbitals alias question
by Elaine Meng 16 Oct '18

16 Oct '18

> On Oct 13, 2018, at 2:34 PM, Benjamin Looker <bgl44(a)cornell.edu> wrote: > > Hello! > My name is Benjamin Looker, I am a chemistry graduate student at Cornell University, and our group often uses Chimera to visualize the orbitals output from the DFT software ORCA. > > When these .cube files are opened in Chimera, the two phases of the wavefunction surface are given different colors and bars in the volume viewer. > > My question is, when using an alias command, how would one set the level and color of only one of these phases, ie: to perform actions on only one of the bars and colors, instead of homogenizing the whole function? > > An alias such as: > alias ^orbitals volume all level 0.05 color #2d2d00000b0b style surface > > Is great, but that pesky "all" undermines the point of the operation. I have tried referencing model numbers, such as #0, #1, and #2 instead of "all," but Chimera returns an error. I do not know the label of the object that I am trying to affect. > > Any help would be greatly appreciated! > Best, > -- > Benjamin G. Looker > Graduate Student > Lancaster Group Hi Benjamin, I don't have an example cube file to test with, but from your description I'm guessing it has signed data and that is why Chimera automatically shows two isosurfaces when you open a single file. The levels are the same magnitude, just the opposite signs. How the initial display values are set is described in the “surface and mesh display” section of the Volume Viewer documentation: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/fram…> "For unsigned data types, an initial threshold is set so that 1% of voxels (1% of the volume encompassed by the data region) lie above it; for signed data types, positive and negative thresholds are placed symmetrically about zero." In that case, there is no way to specify in the command line changing only one isosurface and not the other. You can see in the Model Panel (open from Favorites) that the entire dataset is listed as one model. Although you could open the data twice and use your volume command on only one copy (specified by the model number as shown in the Model Panel) that would still leave both the isosurfaces on the other copy as initially shown. However, there is nothing magical about the initial display setting other than it is meant to be easily viewable. There is no knowledge used about the type of data (i.e. it doesn’t care or know that orbitals are what you’re showing) so you may want to go ahead and set all the isosurfaces using your values rather than relying on initial display. You can specify level and color multiple times in the volume command for multiple isosurfaces, e.g. volume #0 style mesh level 0.8 color red level 1.2 color 0,.5,.8 This is one of the examples in the “volume” command manpage <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/volume.html> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco P.S. for future reference, the chimera-dev list is mainly for programming questions. General usage questions are better sent to chimera-users(a)cgl.ucsf.edu CC’d here

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Visualize 3-10 helix
by BuddySphinx 15 Oct '18

15 Oct '18

Dear Chimera users, I am wondering if there is a quick way in Chimera to visualize 3-10 helix? Or showing the dihedral angle of the peptide bonds? Best, Yangqi Sent from Mail for Windows 10

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problem with autodock vina page
by ammad aslam 13 Oct '18

13 Oct '18

I wonder, is there any problem with autodock vina website vina.scripps.edu/download.html ? I and my friends here cannot open it. Can anyone update me about the real problem. Regards, Ammad

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Morphing code
by Minh Le 12 Oct '18

12 Oct '18

Hello there, I'm currently having trouble with the morphing code in chimera and I don't know how to use Python to make the morph.py. Is there any way you can help me with this? Thank you, Minh

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MD movie metafile
by Matthias Fellner 12 Oct '18

12 Oct '18

Good day I successfully loaded NAMD psf/dcd files into chimera (version 1.13.1) using the tools MD movie interface. As I have many runs and each has multiple dcd files I wanted to use a script to load the different runs, instead of manually picking all the files through the interface each time. I tried to follow the limited instructions of the MD Movie homepage but failed to get anywhere. I tried some versions of this command: md: D:\script.txt or movie: D:\script.txt The command md appears to try to start MDA (MultiDomain Assembler), the command movie wants some other unrelated inputs. I am also not sure if the script command would even work like this: namd(psf/dcd) D:\structure.psf structure_MD001.dcd - D:\ Any advice is appreciated Thank you Matthias Fellner

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Generating symmetry mates
by Vani Pande 10 Oct '18

10 Oct '18

Hello, I wanted to generate symmetry mates for the protein, I am not finding a way to do so in chimera.The protein is a monomer in an asymmetric unit. Thanks Vani Pande Int PhD Biological sciences IISER Pune 20162013

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C-N peptide bond within one peptide
by Emily Xu 08 Oct '18

08 Oct '18

Hello, Is there a way to join two ends of a peptide in Chimera? I am trying the create a peptide bond linking the C and N termini in a singular peptide to form a cyclotide. Is this possible in Chimera?

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Chimera-users October 2018