The ABINIT Users Mailing List ( CLOSED )

[Valerio Olevano <valerio.olevano@polytechnique.fr>]

> Dear Ab-init users,
> 
> I'm actually using GW for cells with a quite large numbers of atoms
> (12 
> or more) and as you know the main problem is the time of the 
> calculations. For GW we have to check the convergence of 6 parameters
> (3 
> for chi, 3 for sigma). Even if some of them don't have too much impact
> on the time, you have to do at least 12 calculations and it's even 
> closer to 20. In the tutorial the convergence is done only for the
> gamma 
> point. I did the convergence studies of a two atoms system for 1 and
> 19 
> k points, it seems that I obtain the same results, I mean for the
> value 
> of the parameter, for the gap I have a big difference. Of course it's
> a 
> lot faster with only the gamma point! So I wanted to know if someone
> as 
> an experience about that? Can we do the convergence studies only for
> the 
> gamma point and after that just run one BIG calculation with the right
> number of k points?
> For me it's working, but I just did one test.
> 
> thanks,
> 
> Johann


Yes, we can.

Valerio