[Wien] Using Monkhorst mesh for SCF

[georg at chem.au.dk]

You are right. The scf cycle doesn't require the k-points to be on a tetrahedral
mes. The calculation of DOS does

 Georg



Quoting Nandan Tandon <nandan at physics.unipune.ernet.in>:

> 
> Please correct me wherever i am wrong, but i understand the following from
> the mails.
> 
> The scf cycle can be run on the user defined k-mesh in .klist file with
> Gauss/Temp/Root option in .in2 file. For the DOS i can generate a k-mesh
> using kgen and then run lapw1 and lapw2 with TETRA option and then
> tetra. This should give a correct DOS for the system.
> 
> Nandan.
> 
> On Thu, 1 Jul 2004, Jorissen Kevin wrote:
> 
> > x_lapw learns that the kgen-file is marked as 'old' (i.e., required) for
> joint (part of the optics package), tetra (for density of states) and nlo_tet
> (??).  It is marked as 'unknown' (i.e., optional) for lapw2 (valence charge)
> and lapwdm (density matrix).  So Georg is right : if you don't need DOS or
> optics, and select another BZ method in case.in2, then you can do without.
> > Should you require one ... I'm afraid the case.kgen-file is a bit of a
> mystery to me.  If you really need one, I'll try to help you.
> >  
> > Kevin.
> > PS the old and unknown refer to the file status flags used for opening
> files in fortran programs, and written in the definition files.
> >  
> > 
> > 	-----Oorspronkelijk bericht----- 
> > 	Van: georg at chem.au.dk [mailto:georg at chem.au.dk] 
> > 	Verzonden: do 7/1/2004 3:46 
> > 	Aan: wien at zeus.theochem.tuwien.ac.at 
> > 	CC: 
> > 	Onderwerp: RE: [Wien] Using Monkhorst mesh for SCF
> > 	
> > 	
> > 
> > 	I don't think you need to generate a kgen file. The kgen file is only used
> by
> > 	the tetra BZ integration method and only makes sence for kpoints on a
> > 	tetrahedral mesh (I thhink). You could simply use ROOT sampling or the
> smearing
> > 	possibilities.
> > 	
> > 	 Georg
> > 	
> > 	
> > 	Quoting Nandan Tandon <nandan at physics.unipune.ernet.in>:
> > 	
> > 	>
> > 	> Dear Kevin,
> > 	>
> > 	> Thank you for your answer. one more detail please.
> > 	> How can the .kgen file be generated from a user defined .klist?? Since
> for
> > 	> tetra the .kgen file is necessary, i want to know how to generate it for
> a
> > 	> given k-mesh?
> > 	>
> > 	> Nandan.
> > 	>
> > 	> On Thu, 1 Jul 2004, Jorissen Kevin wrote:
> > 	>
> > 	> > You can always define your own k-mesh  instead of using kgen, and make
> your
> > 	> own .kgen and .list files, or add k-points to case.in1.  You'll find
> some
> > 	> info about this in the UG, I believe.  It's the same as using a special
> mesh
> > 	> for bandstructure plotting, only now you change the mesh before and not
> after
> > 	> SCF.
> > 	> > 
> > 	> > Kgen prepares only one kind of k-meshes (unless you go into the code
> ... I
> > 	> think it's possible to switch of some sort of correction there which
> > 	> effectively reduces the method to an older, less accurate method ... 
> But I
> > 	> cannot remember how to do this, and what the result will be).
> > 	> > 
> > 	> > Kevin.
> > 	> > 
> > 	> >
> > 	>
> > 	> _______________________________________________
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> > 	>
> > 	
> > 	
> > 	--
> > 	Georg Madsen
> > 	Department of Chemistry
> > 	Aarhus University
> > 	DK-8000 Ã
rhus C
> > 	Denmark
> > 	tlf (+45) 89423885
> > 	
> > 	_______________________________________________
> > 	Wien mailing list
> > 	Wien at zeus.theochem.tuwien.ac.at
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> > 	
> > 	
> > 
> > 
> 
>
******************************************************************************
> Nandan Tandon
> Research Student
> Department of Physics,
> University of Pune
> Pune-411007                             Tel.(O)5692678 ext 426
> MAHARASHTRA, INDIA.                     
>
******************************************************************************
> 
> 
> 
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-- 
Georg Madsen
Department of Chemistry
Aarhus University
DK-8000 Århus C
Denmark
tlf (+45) 89423885