[Wien] symmetry operation

[Javad Hashemifar]

In addition to the explanation of Kevin Jorissen, the easiest way to lower the
symmetry is to use from labels. If you add label to an atom, then this atom
will be inequivalent to all atoms of the same kind. In this way you do not need
to create defect or impurity.

Regards,
Javad Hashemifar

--- Jorissen Kevin <Kevin.Jorissen at ua.ac.be> wrote:
> I'm afraid your situation is not entirely clear to me.
>  
> As has been pointed out repeatedly, if you want the supercell to have a lower
> symmetry than the simple system has, then you need to lower the symmetry,
> right?  By introducing some defect , by changing atom positions...- which is
> usually the whole point of the supercell calculation.   If wien finds
> symmetry higher than the subgroup you mention, then maybe you have not
> sufficiently lowered the symmetry of your unit cell.
>  
> If  (eg. for having a pure reference system) you want to run the symmetric
> cell without making use of its full symmetry, then you either have to edit
> files manually and introduce the correct equivalency and sym ops personally,
> or (easier and safer) introduce a defect before starting with nn and removing
> it before running lstart (make sure that case.inst is correct ...).  This
> requires a little familiarity with wien.
>  
> If you think you're doing everything the right way and wien is making
> mistakes, you'll have to try harder to convince us.  Sending a struct-file
> and explaining in a little more detail what it is that you want to do, might
> be a good idea.
>  
>  
> Good luck,
>  
> Kevin.
>  
> 
> 	-----Oorspronkelijk bericht----- 
> 	Van: Dong YuHui [mailto:dongyh at ihep.ac.cn] 
> 	Verzonden: ma 7/5/2004 4:04 
> 	Aan: wien at zeus.theochem.tuwien.ac.at 
> 	CC: 
> 	Onderwerp: [Wien] symmetry operation
> 	
> 	
> 
> 	Dear WIEN user,
> 	
> 	I want to do some calculation for the phase transition from Wurzite to
> 	Cubic. It is better to built a "supercell" with the space group of the
> 	common subgroup of hex. and cubic, when using GGA. But WIEN2k always find
> 	the symmetric operation as the hex. or cubic, not the ones of my subgroup
> 	and make errors in calculation.
> 	How to overcome this problem?
> 	
> 	Yuhui Dong
> 	
> 	_______________________________________________
> 	Wien mailing list
> 	Wien at zeus.theochem.tuwien.ac.at
> 	http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> 	
> 	
> 
> 

> ATTACHMENT part 2 application/ms-tnef name=winmail.dat




		
__________________________________
Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!
http://promotions.yahoo.com/new_mail