[Pw_forum] convergence problems using GIPAW

[Davide Ceresoli]

On Tue, 27 Oct 2009, Gregor Mali wrote:

> Dear PWscf/GIPAW users,
>
> When doing test calculations with GIPAW module on a Li-Mn-oxide, after
> relaxing the structure, checking the convergence with respect to ecutwfc
> (80 or more), convergence threshold (1d-10 to 1d-12), and number of k
> points (4 4 4 or more), I was able to calculate hyperfine and
> quadrupolar couplings. However, attempts to calculate NMR shifts and g
> tensors always resulted in messages that convergence could not be
> reached.
> In gipaw the convergence threshold is by default set to 1d-14. And the
> error or warning messages in my case always mentioned the accuracy of
> only 1d-5 or 1d-6:

Hi Gregor,
     is your system metallic?

Davide

> Can anybody, please, give me some advice on how to circumvent the
> problem?
>
> Thak you very much.
>
> Best regards.
> Gregor Mali