The ABINIT Users Mailing List ( CLOSED )

[Anglade Pierre-Matthieu <anglade@gmail.com>]

Hi,

There is not much differences between diemac = 1 (means no
preconditionning at all) and diemac = 2 (means that the residuals
changes of the largest G vector will be divided at most by two). Yet
both are quite different from the default diemac = 1e6 which divide
the residual of the largest G vectors by 1e6.

Note that diemac influence only the rate of convergence. Whatever its
value, if your calculation converge to the single ground state, it
will give the same results whatever the value of diemac.

Does this answer your question ?

regards

PMA

On Sun, Jun 14, 2009 at 1:09 AM, Rob<spamrefuse@yahoo.com> wrote:
>
> Hi,
>
> I'm using 5.7.4 with the corresponding Tutorials.
>
> The variable diemac is rather confusing to me and
> hence I 'blindly' follow the guidelines of the user guide.
>
> In Tutorial 1 and 2, on the H2 molecule, all the given input
> files have diemac = 2, as is recommended by the guidelines.
> However, only in lesson 1.5 suddenly the diemac is 1.
> Is this a typo in the t15.in input file, or is this intentionally?
>
> If it's intentionally, it needs an explanation as to why diemac
> must change in this case.
>
> Thank you!
>
> Rob.
>
>
>
>



-- 
Pierre-Matthieu Anglade