[Wien] Antiferromagnetic calculation & EFG !!

[Stefaan Cottenier]

>  What the meaning of EFG ? I think that this parameter is a tensor but 
> the result of wien2k is a number !

No, wien2k gives you all the components of the tensor:

:EFG001:                        EFG         =    24.11651   *10**21  V / 
m**2
                               V20  TOT/SRF=   -11.02902    -0.04086   
<=====
                               V22  TOT/SRF=    17.67855     0.04749  
<=====   These 5 numbers are the tensor in
                               V22M TOT/SRF=     1.57880     0.00406  
<=====  its spherical form
                               V21  TOT/SRF=     0.00000     0.00000  <=====
                               V21M TOT/SRF=     0.00000     0.00000 =======

             24.04616    1.57880    0.00000       24.11651    0.00000    
0.00000
              1.57880  -11.31094    0.00000        0.00000  -11.38130    
0.00000
              0.00000    0.00000  -12.73522        0.00000    0.00000  
-12.73522

And the 3x3 matrix above is the tensor in its cartesian form (traceless 
symmetric matrix). Left: in the global axis system. Right: in the local 
axis system.

>  How can we find that the ground state of a system is ferro or antiferro ?
>  for example  Etot can help us to find that which structure is the 
> best . Is there any parameter to help us for finding the ground state 
> (ferro or antiferro) ?

Again with E_tot: calculate E_tot for the ferromagnetic or 
antiferromagnetic structure (preferably with the same cell size), and 
compare them.

Stefaan


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