[Wien] Problem regarding generating structure with hexagonal unit cell (P6_3/mmc)

[Laurence Marks]

My best guess is that you have atomic positions such as 0.3333 0.6667
which have to be 0.33333333 0.66666667, i.e. high accuracy.

This problem is patched in more recent versions, and you are using a
very old version.

Of course, since you have opted not to provide sufficient information
about your structure this is just a guess, and could well be wrong. If
you want sensible responses you MUST provide more information.

On Mon, Feb 11, 2013 at 8:06 AM, Santu Baidya <santubaidya2009 at gmail.com> wrote:
> Dear wien2k users,
>            I am using wien2k version 07.3 (Release 13/8/2007). I am facing a
> problem in initial structure generation for a crystal with hexagonal unit
> cell (space group:P6_3/mmc). I used w2web to generate the structure with
> space group P6_3/mmc (194) with lattice parameters of hexagonal cell a=b and
> c and gamma=120 deg. The coordinates of atoms were also given for hexagonal
> cell.
>
>  But after generating the case.struct few of the equivalent positions are
> same and as a result I am getting more no. of equivalent atoms corresponding
> to an ineqivalent position than original no. of eqivalent atoms (as can be
> seen from wyckoff positions)
>
> When I ran init_lapw I found the following error:
>
>>   sgroup    (17:17:30) Error: duplicated atoms found! Atoms #3 and #9
>> coincide.
> diff: case.outputsgroup: No such file or directory
> Error: duplicated atoms found! Atoms #3 and #9 coincide.
> 0.000u 0.000s 0:00.00 0.0%    0+0k 0+0io 0pf+0w
> error: command   /opt/WIEN_NEW/sgroup -wi case.struct -wo case.struct_sgroup
> -set-TOL=0.00001   failed
>
> Could any one please tell me about what is the reason behind it. I searched
> previuos wien2k mails regarding such problems with heaxagonal cell but I
> could not find such problem. From rhombohedral cell it is mentioned that
> lattice parameters should be given in hexagonal units. But is there any such
> restrictions over hexagonal unit cell.
>
> Please tell me if there is any solution of this problem.
>
>
> Thanks in  advance.
>
> Santu Baidya
> SRF,
> SNBNCBS
> kolkata-700098
>
>
> "The happiest people do not always have the best of all,  they simply
> appreciate  what they find on their way!!!" SANTU



-- 
Professor Laurence Marks
Department of Materials Science and Engineering
Northwestern University
www.numis.northwestern.edu 1-847-491-3996
"Research is to see what everybody else has seen, and to think what
nobody else has thought"
Albert Szent-Gyorgi