CCL:G: Torsion angles

Yohann, is there a way to specifiy all the atoms in a molecule or specific atom types, eg carbon? Also, would this print to a specified filename or a specific type that should be named in the line or is the "file.log" specific to each molecular calculation? Thanks, David

On Fri, Sep 21, 2012 at 1:48 AM, MOREAU Yohann 224609 yohann.moreau:_:cea.fr <owner-chemistry a ccl.net> wrote:
Dear Sergio, 

By default, in Gaussian, optimizations are done in redundant internal coordinates. If you check your output file, you'll find at the beginning and at the end of the optimization the set of redundant internal coordinates.
To extract these data, you can use a simple shell command, such  as : 

 grep "! D" file.log | awk‘{print $3, " ", $4}' 

Which will output the dihedral parameters (at least those used by the optimizer) at the beginning and at the end of the optimization. 
You can redirect this to another grep filter to find the torsional angle you're looking for : 

 grep "! D" file.log | awk‘{print $3, " ", $4}' | grep "1,2,4,5" 

Which outputs the dihedral value between atoms 1, 2, 4 & 5 at the beginning and at the end of  the calculation.

I'm pretty certain that more "elegant" ways to do it exist but this has worked on my output files.
Anyway, nothing guarantees that the specific torsion angle you're looking for is actually being used by the optimizer and then listed.

I hope this will help you.

YM

-- 

Yohann Moreau

Maître de Conférence, Université Joseph Fourier
iRTSV/CBM/MCT, CEA Grenoble
17 avenue des Martyrs
38 054 Grenoble Cedex 09
Tel. : (33) 4 38 78 29 62
Fax : (33) 4 38 78 54 87

De : "Sergio Manzetti sergio.manzetti[-]gmx.com" <owner-chemistry*|*ccl.net>
Répondre à : CCL Subscribers <chemistry*|*ccl.net>
Date : jeudi 20 septembre 2012 18:01
À : MOREAU Yohann 224609 <yohann.moreau*|*cea.fr>
Objet : CCL:G: Torsion angles

Dear CCLrs can you recommend a program that can easily report the torsion angles of given atoms in a Gaussian output file?

Thanks

Best wishes

Sergio