[Wien] DyFe3

[Gavin Abo]

Care must be taken with R spacegroups since WIEN2k needs mixed lattice 
parameters and atomic positions for them (hexagonal/rhombohedral) [ 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg05554.html 
].

The cif files are not always specified with values having enough 
precision.  WIEN2k needs values specified to meet its full precision (it 
can be particularly important with R or H lattices when there are 
positions having values like 1/3 and 2/3) [ 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10198.html 
, 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg07109.html 
, 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14955.html 
].

The cif2struct is not able to handle the format of some cif files [ 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg07062.html 
, 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10478.html 
, 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg10836.html 
].  So, it could be said that cif2struct works well most of the time, 
but I wouldn't fully trust it in all cases.  In other words, I recommend 
checking the conversion by hand or with the help of another tool like 
SETSTRU [http://www.cryst.ehu.es/cryst/setstru.html].

The difference looks like it might come from one of the Fe atomic 
positions. DyFe3.struct seems to be the better one to use as it has the 
R lattice with 166 R-3m spacegroup.

DyFe3.cif atomic positions:

Dy1 0 0 0.1414
Dy2  0 0 0
Fe1 0.5002 0.4998 0.0829
Fe2  0 0 0.3336
Fe3 0 0 0.5

DyFe3_mp-1101819_symmetrized.cif atomic positions:

Dy1  0  0  0.141689
Dy2  0  0  0
Fe1 0.001445  0.500723  0.081292
Fe2  0  0 0.667138
Fe3  0 0 0.5

DyFe3.struct lattice, space group, and atomic positions:

R   LATTICE, 166 R-3m

Dy1 0.1414 0.1414 0.1414
Dy2 0 0 0
Fe1 0.0825 0.5831 0.5831
Fe2 0.3336 0.3336 0.3336
Fe3 0.5 0.5 0.5

DyFe3_mp-1101819_symmetrized.struct lattice and atomic positions:

H   LATTICE

Dy1 0 0 0.141689
Dy2 0 0 0
Fe1 0.001445 0.500723 0.081292
Fe2 0 0 0.667138
Fe3 0 0 0.5

On 3/28/2019 3:24 PM, sherif Yehia wrote:
> Dear  Users and experts
>
>    I am interested in calculating magnetic properties for DyFe3 found 
> two sources for the DyFe3.cif
>
>   1- got DyFe3.cif file from
>
> http://07110yoph.1104.y.https.materials.springer.com.mplbci.ekb.eg/isp/crystallographic/docs/sd_0251244 
> (Attached)
>
>     I used cif2sruct to  get the strucutre file DyFe3.struct
>
>    2- another .cif file from
>
>     DyFe3_mp-1101819_symmetrized.cif
>
> https://materialsproject.org/materials/mp-1101819/# (Attached )
>
>     I used cif2sruct to  get the strucutre file
>
>     DyFe3_mp-1101819_symmetrized.struct
>
>   My  question is  why they are not the same
>    I hope you can point my mistake
>
>    Thank you all for the help
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