[Pw_forum] very large value 'U' obtained for 'GaAs' by linear response method

[Matteo Cococcioni]

Dear Bramha,

in J. Phys.: Condens. Matter 22 (2010) 055602 we did a similar
calculation but we got pretty different numbers (see Table 2 of the
reference). Maybe the states of Ga you applied U or alpha to are
completely full. what is the value of l set for Ga in set_hubbard_l ?
did you change that? also, for Ga, you better use a pseudo with 3d
states in the valence rather than frozen in the core.

Matteo



On Sun, Oct 7, 2012 at 7:31 AM, Bramha Pandey <pandey.bramha at gmail.com> wrote:
> First of all thank you very much Dear Prof.Stefano.
> I have change the input as ZB 'GaAs' structure and calculate the 'U' value
> for both 'Ga' and 'As' which is given bellow.
> But i wondered to see the 'U' value of 'Ga' 1010.79 which is quite large so
> how can i figure out this is  correct or wrong?
> No of Atom        U_Ga                       U_As
> 2                1043.35792360332    2.87817590827985
> 16              1010.81003743078    2.82970777976411
> 54              1010.79529573193    2.82968584264055
> 128             1010.79528904780    2.82968583269392
> 250             1010.79528904476    2.82968583268940
> Any comment is welcome.
> --
> Thanks and Regards
> Bramha Prasad Pandey
> Ph.D Student Indian School of Mines(ISM)
> Dhanbad, INDIA.
>
>
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-- 
Matteo Cococcioni
Department of Chemical Engineering and Materials Science,
University of Minnesota
421 Washington Av. SE
Minneapolis, MN 55455
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