[Wien] No convergence during Volume Optimization

[pieper]

Look at the curve energy vs. volume and decide yourself wether its worth 
the while to increase the number of iterations (assuming that's the 
reason for the 'jump to the next point').

It also is a good idea to look for reasons why the convergence is slow 
(problem in the struct file? Bad position for some atom? Lattice 
constants very far from equilibrium? ... there are a lot of less trivial 
possibilities)

Concerning your other question wether or not optimization with respect 
to energy or with respect to forces is the same I recommend reading the 
section on structure optimization in the user guide, and perhaps the 
'Optimization Notes' of L. D. Marks that you will find on the Wien2k 
website. I am completely unable to improve on those.

Best luck

Martin Pieper


---
Dr. Martin Pieper
Karl-Franzens University
Institute of Physics
Universitätsplatz 5
A-8010 Graz
Austria
Tel.: +43-(0)316-380-8564


Am 12.11.2016 12:31, schrieb Abderrahmane Reggad:
> Dear Wien Users
> 
> Sometimes , It happens that during volume optimization , the
> calculation doesn't converge to the chosen energy criteria and jumps
> to the next point . In this case, should we delete this point and
> choose another point or we could accept this calculation.
> 
> For example , with energy criteria value of 0.0001 and with some
> points (we take 3 points as example)/
> 
> -  6 percent point:
> 
> ETEST: .00083
> 
> - 0 percent point:
> 
> ETEST: .00034
> 
> - 6 percent point
> 
> ETEST: .00013
> 
> Best regards
> 
> --
> 
> Mr:
> A.Reggad                                          
> 
> Laboratoire de Génie Physique
> Université Ibn Khaldoun - Tiaret
> 
> Algerie
> 
> 
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:
> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html