The ABINIT Users Mailing List ( CLOSED )

[Masayoshi Mikami <mmikami@rc.m-kagaku.co.jp>]

Hi there,

One more thing that I would like to confirm:
which ionic configurations for Y and Ta pseudopotentials
were adopted, respectively ?

As noted in ~ABINIT/doc/psp_infos/psp1_data.txt
(thanks to Doug and his coworker, A. Khein !),
oxides may need shallow-core "valence" electrons
for alkaline-earth elements etc. This may hold true
with rare-earth elements and transition metals.
Thus, Y may be +11 cation, and Ta may be +13 cation.

On the HGH pseudopotential page:
http://www.abinit.org/Psps/?text=../Psps/HGH/hgh
click the green part, then we can download the pseudopotentials
with semi-core... (This semi-core PP should be much harder !)

It is not straightforward but not so difficult to make
TM pseudopotentials with semi-core valence states.
It may be a good occasion to learn to make them by oneself.
Visit FHI98PP and/or OPIUM pseudopotential package WEB,
and run through the tutorials available in the packages.
        http://www.fhi-berlin.mpg.de/th/fhi98md/fhi98PP/
        http://opium.sourceforge.net/

Before running the computation of the ternary compound,
one may want to compute binary compound to check the
transferability. (i.e. Y2O3 and Ta2O5) In this case, they
may be heavier calculations than the original computation.
(e.g. Y2O3 needs 40 atoms, as appeared on this ML the other day)

Regards,
Masayoshi

On 2007/06/11, at 16:55, Anglade Pierre-Matthieu wrote:

> Hi,
>
> The behaviour you describe with HGH pseudopotentials is quite  
> uncommon except for the fact they are hard. Paul Boulanger noticed  
> that you use todfe=1e-5. This might be the source of all your  
> problem both with HGH and your relaxation.  Try to use something  
> largely more converged. (toldff 1e-6 for instance for your  
> relaxation).
>
> Strfact is a simple factor that allows using strains as forces in  
> the relaxation process. Consider that this changes your strain to  
> forces applying on the "walls" of your cell. The overall effect is  
> simple:  the bigger is this factor the more strain will be optimized.
>
> regards
>
> PMA
>
> On 6/11/07, xd0533@163.com <xd0533@163.com> wrote: dear PMA;
> I tried HGH pseudopotentials.Its ecut is very high.For different  
> ecut(I choose ecut from 60 to 100),the total energy is in big  
> difference(2eV).The total energy is changeable all the time.It is  
> hard to converge in ecut.Higher ecut,more time.So,I give up  HGH  
> pseudopotentials.
> I saw  the parameter strfact.But its explaination is simple.I don't  
> understand it.Can you show me how to settle  the parameter?Thank you!
> Best wishes!
> xiang
>
>
>
> --
> Pierre-Matthieu Anglade