[Wien] Supercell structure co-ordinates are different in Wien2k and PHON

[Fecher, Gerhard]

I am not familar with VASP and this is the Wien2k Forum here,
but I know that there is no need to give the name of the atoms in POSCAR
the line 16 16 16  means 16 atoms of the first kind 16 of the scond and 16 of the third
and there are 3 times 16  positions  in the list
and the lattice is cubic primitive as seen from the matrix 
the result is something like XYZ instead of X2YZ
I guess PHON gave the correct answer on the wrong question.
(Remember, the ERROR is always sitting 30 cm (1ft. for Americans) in front of your monitor ;-)

I like much more to use the correct space groups then to give the matrix by hand.

Phonophy suggest for Wien2k to use P 1 in cases where the construction of the Hellman Feynman forces failes.

I have only experience with Wien2k and Phonon of Parlinsky and had no problems with the produced struct files with different superstructure sizes.

Ciao
Gerhard

DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
"I think the problem, to be quite honest with you,
is that you have never actually known what the question is."

====================================
Dr. Gerhard H. Fecher
Institut of Inorganic and Analytical Chemistry
Johannes Gutenberg - University
55099 Mainz
and
Max Planck Institute for Chemical Physics of Solids
01187 Dresden
________________________________________
Von: wien-bounces at zeus.theochem.tuwien.ac.at [wien-bounces at zeus.theochem.tuwien.ac.at] im Auftrag von Lyudmila Dobysheva [lyuka17 at mail.ru]
Gesendet: Freitag, 5. Dezember 2014 09:20
An: A Mailing list for WIEN2k users
Betreff: Re: [Wien] Supercell structure co-ordinates are different in Wien2k and PHON

On 04.12.2014 01:22, venkatesh chandragiri wrote:
> The initial structure file contains 12
> atoms with a primitive type.Now, I have generated 2x2x2 supercell using
> the same struct file (contains 12 number of atoms) in both Wien2k and
> PHON programs. For Wien2k, depending on the selection of the output
> lattice (FCC, BCC, primitive), the number of atoms would change.
> For primitive = 96 atoms, BCC = 48 atoms, FCC = 24 atoms.

I have a feeling that some misunderstanding exists here: all three
variants of WIEN2k contain 96 atoms (which is correct),
your SPOSCAR file contains only positions which correspond to iron atoms
in the FE2VAl.struct file.
No information on the type of atoms is in the SPOSCAR file at all.
Start from this - here is something wrong, and then think about symmetry
P1 also.

Best wishes
   Lyudmila Dobysheva
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