[Wien] Partially Occupied Wyckoff site

[Xavier Rocquefelte]

Dear Farshad,
As  mentionned by Pascal you must use a supercell.
For instance, if you use a small supercell with 2a x 2b x c, you will 
have 8 positions for the 2a site. In such a sitiuation you will be able 
to do the following occupation:
- 1Li and 7 Fe, i.e. occupations of 0.125/0.875
- 2Li and 6Fe, i.e. occupations of 0.25/0.75
- 3Li and 5Fe, i.e. occupations of 0.375/0.625
- 4Li and 4Fe, i.e. occupations of 0.5/0.5
- 5Li and 3Fe, i.e. occupations of 0.625/0.375
- 6Li and 2Fe, i.e. occupations of 0.75/0.25
- 7Li and 1Fe, i.e. occupations of 0.125/0.875

For such a small supercell the chemical composition closer than the 
experimental one is 2Li and 6Fe, i.e. 25% of Li and 75% of Fe.
Then you will have to test different atomic arrangements to insure that 
you have no artificial results due to some non-realistic ordering.
The present supercell is certainly too small but it can be a good 
starting point to feel the related physics and it depends on the 
property you are looking for.

Cheers
Xavier


Le 01/06/2015 15:48, Farshad Nejadsattari a écrit :
> Dear Wien2k community,
>
>   I am working on an Iron Selenide superconductor with a formula 
> (Li0.8Fe0.2)OHFeSe. The 5 Wyckoff positions are given below:
>
> Inline image 1
>
> My question is how can one include the Li/Fe1 contribution in the 
> master case.struct file as the 3rd position is partially occupied by 
> Lithium (81 percent) and partially by Iron (19 percent).
>
> your assistance is truly appreciated.
>
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20150601/4ecc7813/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/png
Size: 19122 bytes
Desc: not available
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20150601/4ecc7813/attachment.png>