[ase-users] Relax with constraints: fixed atoms and fixed dihedral

[Jens Jørgen Mortensen]

On 10/12/2016 01:52 PM, Alessandro Pirrotta via ase-users wrote:
> Dear ASE community,
>
> I am trying to relax a molecular junction with pbc with 2 types of 
> constraints:
> 1) contact atoms position fixed;
> 2) a dihedral within the molecule fixed.
>
> The relaxation step crashes the calculation giving the attached error 
> output.
> I don’t know weather this belong to the GPAW mailing list.
> I have attached also copy of the script lines responsible for this 
> error: I have used the same script without dihedral constraint but 
> with FixAtoms previously and it works just fine. so I believe 
> FixInternals is the cause.

I think the correct syntax is:

     ccc = FixInternals(dihedrals=[dihedral1])

Does that help?  If not, then try to update to ase-3.11 and gpaw-1.1.

Jens Jørgen

>
> Can anybody help?
>
> Cheers,
> ——
> *Alessandro Pirrotta*
> PhD student
>
> *Faculty of Science**
> *Department of Chemistry &
> Nano-Science Center
> University of Copenhagen
> Universitetsparken 5, C321
> 2100 Copenhagen Ø
> Denmark
>
> DIR +45 21 18 11 90
> MOB +45 52 81 23 41
>
> alessandro.pirrotta at chem.ku.dk <mailto:alessandro.pirrotta at chem.ku.dk>
> http://nano.ku.dk/english/research/nanochemistry/solomon_group/
> www.ki.ku.dk <http://www.ki.ku.dk/>
>