[Pw_forum] DFT+U: about how to get U

[Chao Cao]

Dear Matteo,
 Thanks for this fast response. I have two more questions.
I am assuming that by "non-equivalent" you mean non-equivalent site
instead of non-equivalent type, i.e. if I have two Fe atoms within 1
unit cell, I'll have to treat them individually, therefore they might
have different U number?

Also, it looks to me that this method is not restricted to d-electrons,
and practically it also applies to p and f electrons, am I right?

Chao Cao

Matteo Cococcioni wrote:
> Dear Chao Cao,
>
> the linear response procedure is repeated only for non-equivalent
> Hubbard atoms.
>
> Regards,
>
> Matteo
>
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> Matteo Cococcioni
> Department of Chemical Engineering and Materials Science
> University of Minnesota
> 151 Amundson Hall
> 421 Washington Av. SE
> Minneapolis, MN 55455
> Tel. +1 612 624 9056    Fax +1 612 626 7246
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
>
> On Oct 16, 2007, at 3:02 PM, Chao Cao wrote:
>
>> Hi there,
>>   I read about M. Cococcioni's paper and thesis on how to get the U
>> parameter, and have the following question on mind:
>>   Does the procedure of perturbing atomic occupation go through every
>> single atom or just "hubbard" atoms? In the latter case, does the
>> response matrix chi include elements related with hubbard atoms only (
>> i.e. chi(m,n) m and n are both hubbard atoms ), or it has to include
>> everything? If it includes everything, what do we do about elements
>> related to non-hubbard atoms (maybe set them to 0 (?))?
>>
>>   Thanks in advance.
>>
>> Chao Cao
>>
>> -- 
>> Chao Cao
>>
>> Quantum Theory Project and Department of Physics
>> University of Florida, Gainesville, FL 32611
>> U.S.A.
>>
>> _______________________________________________
>> Pw_forum mailing list
>> Pw_forum at pwscf.org <mailto:Pw_forum at pwscf.org>
>> http://www.democritos.it/mailman/listinfo/pw_forum
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>   


-- 
Chao Cao

Quantum Theory Project and Department of Physics
University of Florida, Gainesville, FL 32611
U.S.A.