[Wien] electrostatic potentials

[Peter Blaha]

I don't know what you have made wrong, but I don't believe that.

You know that the potential will be in Ry (not Hartree !), which makes
a factor of two!

PS: An atom in a supercell you would always do with just ONE k-point
You also have to make sure you are calculating/comparing the right thing.
Many atoms need spin-polarization! and in GGA you may obtain a
"non-spherical" atom (at least when you break cubic symmetry);
i.e. in carbon two 2p-orbitals (with spin-up) might be fully occupied
while the 3rd one is empty,.... leading to non-spherical potentials
(visible further away from the nucleus).

simon.kurasch at uni-ulm.de schrieb:
> Dear Wien2k users,
> 
> I want to work with the coulomb-potentials created by Wien2k out of  
> the file case.vcoul.
> For comparison with potentials from isolated atom models (like Doyle  
> Turner or potentials by Kirkland) I put one atom (C or Ag) into a 10  
> ANG primitive cell and run SCF using gga -6Ry, about 200 K-points (I  
> also performed calculations with 1000K) and krmax 7. Afterwards I used  
> lapw5 to create linescans of vcoul. lapw5.def and case.in5 are shown  
> below.
> 
> There are big deviations: in the range of 0.1-0.3 Ang from the core  
> the Wien2k potential is about a factor of 2 smaller and from 0.6-1.5  
> Ang the Wien2k potential is a factor of 2 larger.
> 
> One idea is to calculate the electrostatic potential form the Wien2k  
> charge density clmsum via Mott equation. Has anyone experience with  
> using this equation? I already tried to implement it using fftw3 but I  
> didn't succeed.
> There's probably already software available to performe these  
> calculations, but I was not able to find it yet.
> 
> I would be very grateful for some help.
> Simon Kurasch
> 
> 
> lapw5.def
> 5 ,'Single_Ag.in5', 'old',    'formatted',0
> 6 ,'Single_Ag.output5',   'unknown','formatted',0
> 8 ,'Single_Ag.struct',    'old',    'formatted',0
> 9 ,'Single_Ag.vcoul',    'old',    'formatted',0
> 10,'Single_Ag.tmp',       'unknown','unformatted',0
> 11,'Single_Ag.vcouldn',  'unknown','formatted',0
> 12,'Single_Ag.sigma',     'unknown','formatted',0
> 20,'Single_Ag.rho_onedim','unknown','formatted',0
> 21,'Single_Ag.rho',       'unknown','formatted',0
> 
> case.in5
> 1  1  1  2
> 2  2  1  2
> 2  2  1  2
> 3  3  3
> 500   1
> RHO
> ATU VAL NODEBUG
> NONORTHO
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-- 

                                       P.Blaha
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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/
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