[gpaw-users] Calculations in LCAO mode

[Ask Hjorth Larsen]

Hi Ulrik

On Tue, 28 Feb 2012, Ulrik Grønbjerg wrote:

> Hi Ask
> 
> Thanks for your help, those changes improved convergence. However, one system still fails to
> converge in 120 iterations, even at linear mixing parameter of 0.02. I am therefore trying with
> 150 iterations as maximum.
> 
> Would you have other tips to improve convergence?
> 
> Best wishes
> Ulrik

You can see whether 0.03 or 0.01 are better, or whether it helps to 
increase the mixing history (I don't have conclusive ideas on how much 
that actually helps).

If the problem is that it simply converges very slowly, an increase of 
maximum number of iterations might be the only solution.

Other parameters that can be experimented with are the Fermi smearing and 
number of empty bands.  I think it is unlikely that they are problematic 
in this case.

The final way is to generate new PAW setups, but I don't think anyone 
knows how to systematically improve convergence this way.

Regards
Ask