[DFTB-Plus-User] Further inquiry on the geometry optimization

[Iresh Shamika]

Sir,
I want to calculate the energy of the molecules as a function of the
changing bong length at different desired values .Even though constrain
option is available it does not have any option to change the bond length
as desired to make as constant .

Thank you,
Iresh Shamika.

On Thu, May 7, 2015 at 12:53 PM, Bálint Aradi <aradi at uni-bremen.de> wrote:

> Dear Iresh,
>
> >  I went through as you instructed but , I could not figure out how to
> > fix the bond distance because it is a transition of open to close
> > .Constrain{} function and the move atom{}  do not have any option to fix
> > the bond length during the ring opening and the closing .
>
> I still do not know, what you plan to do, so hard to give any advice.
> You can not relax structures or make MD in DFTB+ with constrained bond
> lengths as we do not have SHAKE or RATTLE implemented. In some cases,
> for example if you calculate some property as function of the bond
> length, however, it could be enough to fix the two atoms making up the
> bonds and relax everything else. If latter works for you, you can do it
> easily with DFTB+. If not, you won't be able to do it right now.
>
>   Best regards,
>
>   Bálint
>
> --
> Dr. Bálint Aradi
> Bremen Center for Computational Materials Science, University of Bremen
> http://www.bccms.uni-bremen.de/cms/people/b_aradi/
>
>
>
> _______________________________________________
> DFTB-Plus-User mailing list
> DFTB-Plus-User at mailman.zfn.uni-bremen.de
> https://mailman.zfn.uni-bremen.de/cgi-bin/mailman/listinfo/dftb-plus-user
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.zfn.uni-bremen.de/pipermail/dftb-plus-user/attachments/20150507/2b7bb2d7/attachment.htm>