[Wien] Transformation from rhombohedral to hexagonal coordinates - swapping of x and y components

[Peter Blaha]

I cannot answer this in general.
All I see from simple tests is that hex2rho and rho2hex are converting coordinates
into each other properly.
WIEN takes sometimes row, sometimes column vectors ....

We would need to look into a specific example where you have some structural
data and need to set them into WIEN2k-format. Then check eg. the nn-distances,
symmetry,....

Juergen Spitaler schrieb:
> Dear Prof. Blaha!
> Recently I have been dealing with the conversion from rhombohedral to
> hexagonal coordinates. I was surprised that the x and y  values I
> obtained for the hexagonal coordinates were just swapped with
> respect to the ones "expected" by sgroup/symmetry
> and the ones obtained by rhomb2hex.
> When I looked into the source of rhomb2hex I found that
> the first and second line of the Bravais matrix for the hexagonal
> lattice are swapped with respect to the lattice vectors given in
> the usersguide. Now my questions are:
> - How can this swapping be explained?
> - Are the coordinates I obtain using the "swapped" hexagonal Bravais matrix
>   compatible with all other parts of the Wien-code?
> 
> Best regards,
> Juergen Spitaler
> 

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                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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