The ABINIT Users Mailing List ( CLOSED )

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

Hi,

Usually, to get the primitive cell you have to check the
stoechiometrie of your conventional cell to decide how many atom you
should include in the primitive cell. Then you have to find some axis
that enclose this formula. It is not always very easy and can require
a lot of 3D drawings ...
Good work.

regards

PMA

On Tue, Sep 16, 2008 at 12:00 PM, Chaitanya Krishna <icymist@gmail.com> wrote:
> Hi all,
>
> I guess I need to apologize first. I actually do not use abinit for my
> daily work. So I don't think I can try the suggestion any time soon.
>
> What I had in mind was not to just use it for abinit, but for
> calculation with any electronic structure program so that I can define
> all the atoms in the primitive cell.
>
> Risking being repetitive, taking the simple case of NaCl, given the
> crystal structure information (lattice parameters, space group,
> inequivalent positions) my output for the primitive cell should be
> something like below,
>
> Fm-3m NaCl
>  0.0    2.82    2.82
>  2.82    0.0    2.82
>  2.82    2.82    0.0
>   1   1
> Direct Coordinates
>  0.0  0.0  0.0
>  0.5  0.5  0.5
>
> In my previous, the space group is Fd-3m (No. 227). I think it was
> misunderstood as Fd-3.
>
> Regards,
> Chaitanya.
>
>
> On Tue, Sep 16, 2008 at 10:59 AM, Anglade Pierre-Matthieu
> <anglade@gmail.com> wrote:
>> Hi,
>>
>> I guess in this case the best is to use abinit spgroup input variable
>> Fd-3 is group number 203 (see
>> http://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-table?from=getwp ).
>> I think that if you do that, you just need to specify the reduce
>> coordinate of the inequivalent atoms you have sent to the forum.
>> However I'm not quite sure vbecause I have never tried. Could you tell
>> us if it work ?
>>
>> regards
>>
>> PMA
>



-- 
Pierre-Matthieu Anglade