[Wien] Hexagonal structure generation

[Peter Blaha]

I hope it is clear for you that when you specify SG 186 in structgen,
you should only give ONE of the equivalent positions:

> Si  0.00000000  0.00000000  0.00000000     
  generated automatically > Si  0.00000000  0.00000000  0.50000000     
> C   0.00000000  0.00000000  0.18750000     
  generated automatically > C   0.00000000  0.00000000  0.68750000     
> Si  0.33333333  0.66666667  0.24982500     
  generated automatically > Si  0.66666667  0.33333333  0.74982500     
> C   0.33333333  0.66666667  0.43732500     
  generated automatically > C   0.66666667  0.33333333  0.93732500    


> Hello,
> I am trying to work with a hexagonal system (186) C46v-P63mc. 
> I generated the template in many different ways but always the space group changes in sgroup.First I chose the particular space group with 4 atoms and gave one position (first position) for all atoms. I also tried with 2 atoms and 2 + 2 positions by chosing H as well as space group 186. In all cases there is a change in space group. I have read the mailing list discussions but have not been able to understand this.
> The inputs were
> 4HSiC    a =3.07, c = 10.06
> Lattice coordinates
> Si  0.00000000  0.00000000  0.00000000     
> Si  0.00000000  0.00000000  0.50000000     
> C   0.00000000  0.00000000  0.18750000     
> C   0.00000000  0.00000000  0.68750000     
> Si  0.33333333  0.66666667  0.24982500     
> Si  0.66666667  0.33333333  0.74982500     
> C   0.33333333  0.66666667  0.43732500     
> C   0.66666667  0.33333333  0.93732500    
> Please suggest how I can get the specific space group (186).
> Thank you in advance,
> Best wishes
> Chandrika
> 


                                      P.Blaha
--------------------------------------------------------------------------
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/
--------------------------------------------------------------------------