[Wien] FeO LDA+U

[Rossitza Pentcheva]

besides the point Peter mentions you should be careful when using the 
fine grain parallelization with LDA+U- LDA+U is not implemented in the 
MPI version (at least this was the state about 9 months ago) and you get 
the normal LDA result - which you could quickly realize when you compare 
the total energies.

Best regards,
Rossitza Pentcheva

Peter Blaha wrote:

>Do you have an AF rhombohedral cell with 2 Fe atoms and one Ni ?
>
>The Fe have opposite spin ?
>
>If I remember correctly, there was no problem in going from GGA to LDA+U
>and getting an insulator. 
>
>However, you can play with the density matrix
>and occupy the d-z2 (m=0) orbital. Use  x org -up/dn and runsp -orbc for
>some steps, until you release it using runsp -orb
> 
>
>  
>
>>I am trying to do an LDA+U calculation for FeO in the antiferromagnetic 
>>configuration (AFM).
>>I find that even when I start the calculation with the antiferromagnetic spin 
>>configuration and a large
>>value of U (up to 9eV, J = 0.89), the system goes back to a metallic 
>>ferromagnetic state.
>>I have tried modifying the density matrices and restarting.In this case, either 
>>the same happens or the
>>Fe magnetic moments wander around and never converge.
>>
>>Has anyone converged a gapped AFM state for FeO?
>>Or at least has anyone noticed the above problem?
>>
>>In the literature it is a mentioned a few times  that one needs to fully occupy 
>>the A1g orbital (rhombohedral system) and deplete the Eg orbitals in order 
>>to open a gap.
>>Has anyone done this successfully for FeO?
>>
>>Was it sufficient to start with a particular configuration or was modification 
>>of the density matrices necessary?
>>
>>Any help you can provide is greatly appreciated.
>>
>>Ashley
>>
>>PS. I am running WIEN2k_04.11 (Release 1/11/2004)
>>
>>
>>
>>
>>
>>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>John Ashley Alford II
>>Oak Ridge National Laboratory
>>PO Box 2008  MS6164
>>Oak Ridge, TN  37831-6164
>>Phone: (865) 576 - 6269
>>FAX:   (865) 241 - 0381
>>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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>>Wien at zeus.theochem.tuwien.ac.at
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>>
>>    
>>
>
>
>                                      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/
>--------------------------------------------------------------------------
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>  
>


-- 

Dr. Rossitza Pentcheva
Department of Earth and Environmental Sciences    phone: +49 89 2180 4352   
Section Crystallography                 fax:   +49 89 2180 4334   
Ludwig-Maximilians-University Munich    e-mail: pentcheva.at.lrz.uni-muenchen.de
Theresienstr. 41         80333 Munich
            www: http://www.krist.geo.uni-muenchen.de/ober/pentche.htm

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