[Pw_forum] too many bands are not converged

[Chad Junkermeier]

I also made the appropriate changes to the lattice constants.



Chad Junkermeier, Ph.D.
NRC Post-Doctoral Fellow
Naval Research Laboratory
4555 Overlook Ave, S.W.
Washington DC 20375







On Mar 23, 2010, at 11:37 AM, Chad Junkermeier wrote:

> Hello Pw_forum,
>  I was working on a model system using a 2x2 supercell, everything  
> worked fine.  I switched a 4x4 system and I repeatedly get the  
> following error:
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
> %%%%%%%%%
>     from c_bands : error #         1
>     too many bands are not converged
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
> %%%%%%%%%
>
> The only changes I made to the input file were nat,  
> ATOMIC_POSITIONS, and K_POINTS.  The changes to nat and  
> ATOMIC_POSITIONS, are obvious due to the increase in cell size.  In  
> moving to the larger supercell I went from
>
> K_POINTS automatic
> 4 4 1  0 0  0
>
> to
>
> K_POINTS automatic
> 2 2 1  0 0  0
>
> What is the general cause of the error?  Is there a change to the  
> input that normally solves this problem?
>
> Chad Junkermeier, Ph.D.
> NRC Post-Doctoral Fellow
> Naval Research Laboratory
> 4555 Overlook Ave, S.W.
> Washington DC 20375
>
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