[Wien] How to calculate U for 3d-fully filled

[Gavin Abo]

As far as I know, two methods are currently used to calculated U in 
WIEN2k [ 
http://www.cms.tuwien.ac.at/media/uploads/cms/psi-presentations/Blaha.ppt (Slide 
10) ]:

1)  Fitting method: Adjust U until the desired results are obtained 
(i.e., until the calculated  results are matched to the experimental 
results)

http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg12261.html
http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg12171.html

The U value is usually picked for the fit so that it minimizes the 
average error among several different properties [ J. Chem. Theory 
Comput. vol. 7 p. 2218 (2011): 
http://pubs.acs.org/doi/abs/10.1021/ct200202g ].

2) Constrained LDA (cLDA) method

http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg11746.html
http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg08794.html
http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg07587.html
http://arxiv.org/abs/1206.3533v2

It is noted that Ueff values obtained from this method are known to be 
of questionable accuracy [ JAP vol. 109 p. 063707 (2011): 
http://dx.doi.org/10.1063/1.3562145 , PRB vol. 76 p. 155123 (2007): 
http://link.aps.org/doi/10.1103/PhysRevB.76.155123 ].

There is a comparison between different constrained DFT methods in the 
file at:

http://www.fhi-berlin.mpg.de/~xinguo/talks/jiang_cdft-coffeetalk.pdf

The linear response method seems to be popular with other DFT software 
like Quantum-ESPRESSO [ 
http://hjklol.mit.edu/content/calculating-hubbard-u ].

I hope the references above help and good luck.

On 5/27/2015 6:45 AM, Tuan Vu wrote:
>
> Dear creators!
>
> I have come across a difficulty in realization your program. Can you 
> explain, how to calculate the parameter U for the case, when the 
> d-subshell is completely full filled.(example Zn, Ag or 5d Hg, Tl, Pb)
>
> I am grateful to you in advance.
>
> Yours sincerely, the third year post-graduate student of Don State 
> Technical University
>