[Pw_forum] about Ueff in LDA+U calculation

[Stefano de Gironcoli]

Dear M Lahmer

 the DFT+U implementation in PWscf is the one described in Phys Rev B 
71, 035105 (2005) by M. Cococcioni and S de Gironcoli.
The U parameter defined in PWscf is directly the U_eff = U-J you are 
referring to and the alpha parameters are used to perturb the system 
away from its LDA minimum, or other reference systems that might be more 
convenient [see PRL 97, 103001 (2006) by Kulik, Cococcioni, Scherlis  
and Marzari], to calculate the U parameter from first principles 
following the recipe given in that paper.

hope this helps,
best regards,
 stefano de Gironcoli - SISSA and DEMOCRITOS

patriot pershing wrote:
> M Lahmer
> Laboratory of physics and chemistry of semiconductors
> university of constantine
>
> 2010/3/17, Stefano de Gironcoli <degironc at sissa.it>:
>   
>> dear patriot
>> please provide your identity and  affilaition
>> best regards,
>> Stefano de Gironcoli - SISSA nd DEMOCRITOS
>>
>> patriot pershing wrote:
>>     
>>> dear please:
>>> i would do LDA+U calculation on ZnS and ZnO material using Quantum
>>> Espresso code and i would use Ueff in my calculations which is defined
>>> as U - J by changing these 2 parameters but when i have traied to do
>>> this using espresso code i don't arrived to do this because only the U
>>> value as well as alpha parameter can be modified for this reason i
>>> would if any one can help me in this point. secondly, i would ask what
>>> i need to do GGA+U calculations? ( i think in espresso is just do
>>> LDA+U calculation + USPP with GGA exchange-correlation function)
>>> best regards
>>> _______________________________________________
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>>> Pw_forum at pwscf.org
>>> http://www.democritos.it/mailman/listinfo/pw_forum
>>>
>>>       
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>>     
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