[Wien] Problem creating struct files from VASP contcar files

[Gus Hart]

At 04:51 PM 1/13/2004 +0200, you wrote:
> > I'm new to using wien 2k, so I hope I'm not missing a simple solution 
> to this.
> >  I'm trying to convert VASP contcar files for low symmetry structures, like
> > monoclinic, into struct files.  A sample contcar file is pasted below.
> >
> > GSS check structure #: 81
> >     4.100000000000000
> >      1.0062816128952770    0.5260273706595530    0.5121801204340521
> >     -0.4948479628567789    1.0535466565671180    0.4948479628567789
> >     -0.4941014924612246   -1.0520547413191060    0.4941014924612247
> >    6   3
> > Direct
> >   0.3333333333333428  0.7607588622281583  0.8969830898152509
> >   0.6694622253955771  0.7390086361365178  0.5980793830199076
> >   0.9972044412710943  0.7390086361365178  0.2619504909576591
> >   0.6694622253955771  0.2609913638634822  0.0713828423756695
> >   0.9972044412710943  0.2609913638634822  0.7352539503134352
> >   0.3333333333333428  0.2392411377718417  0.4363502435180777
> >   0.3333333333333428  0.0000000000000000  0.6666666666666572
> >   0.6680618367231830  0.5000000000000000  0.8340309183616057
> >   0.9986048299434884  0.5000000000000000  0.4993024149717371
> >
> > The first line (after the title) is the scale factor, the next three lines
> > define the basis vectors, and the nine atom positions are listed in direct
> > coordinates.  Using StructGen, I entered a=5.105, b=5.187, c=5.178 and
> > alpha=112.8, beta=120.5, gamma=78.6.  The atom positions were entered in
> > direct coords as above.
> >
> > When I run init_lapw it keeps identifying it as a triclinic 
> structure.  I have
> > also tried placing a single atom at 0,0,0 to see if it would show up as
> > monoclinic, but it doesn't.
> >
>
>Well, sgroup does perform a correct job, only you need to specify all
>the numerical values with maximal possible precision. The value for a is
>5.1071519 (not 5.105) the value for b is 5.1856647 (not 5.187)
>for c is 5.1781746, alpha, beta and gamma are 112.81407 120.46110 78.66372.
>On these numbers and single atom at (0,0,0) sgroup is able to
>find monoclinic base centred cell, so, what you need is accurately
>specify all the atomic positions and parameters of the unit cell.

Wow, Bogdan. If what you say is true then we can use WIEN2K after all. 
We'll give it a try right away.

Thanks!
-Gus

> > The atom positions were entered in direct coords as above.
>
>Probably that's wrong, because the positions must be specified as fractions
>of the lattice vectors (not cartesian coordinates), transformation
>is needed.
>
>Regards,
>Bogdan Yanchitsky
>
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++++++++++++++++++++++++++++
Gus Hart   (Rm. 312)
Department of Physics and Astronomy
PO Box 6010
Flagstaff AZ 86011-6010
tel. (928)523-0426
fax (928)523-1371
gus.hart at nau.edu
http://www.physics.nau.edu/~hart