[Pw_forum] about GGA+U calculation

[Bipul Rakshit]

Thanks Prasenjit for the suggestion.
So if I use Hubbard_U(1) =12.0, Hubbard_U(2)=6.5,
so does it mean that the U applied in Zn- d states and Oxygen p-state only?
Or is there any tag to specify the orbitals like we can do in VASP.
regards

On Wed, Dec 24, 2014 at 1:17 PM, Prasenjit Ghosh <prasenjit.jnc at gmail.com>
wrote:

> Dear Bipul,
>
> ZnO is tricky.......if you are interested in correct band gap opening and
> positioning of the VBM and CBM, you need to apply U on both Zn and O. The
> recommended values are 12 and 6.5 eV for Zn and O respectively (see  J. Am.
> Chem. Soc. 2011, 133, 5893-5899). However, unlike other cases, these does
> not have a physical significance.
>
> Prasenjit
>
> On 24 December 2014 at 10:41, Bipul Rakshit <bipulrr at gmail.com> wrote:
>
>>
>> Dear PWSCF users,
>> I am doing GGA+U calculation for ZnO wurtzite structure. I attached the
>> input file for the same.
>> My doubt is for using "Hubbard U" we are using two additional tags
>> (compared to simple GGA calculation)
>>                lda_plus_u = .true.,
>>               Hubbard_U(1) =8.0, Hubbard_U(2)=0.0,
>>
>> So I am applying Hubbard U=8 eV on my first species (i.e. Zn) and 0.0 eV
>> on Oxygen.
>> But how can I understand that this Hubbard U of 8 eV is applied on Zn- d
>> states?
>> or do I have to specify some additional tags or something?
>>
>> Kindly help in this matter.
>>
>> Thanks
>> --
>> Dr. Bipul Rakshit
>> Research Associate,
>> Institute of Physics (IOP),
>> Bhubaneswar- 751 005
>> Orissa
>> India
>>
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>>
>
>
>
> --
> PRASENJIT GHOSH,
> IISER Pune,
> Dr. Homi Bhabha Road, Pashan
> Pune, Maharashtra 411008, India
>
> Phone: +91 (20) 2590 8203
> Fax: +91 (20) 2589 9790
>
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>



-- 
Dr. Bipul Rakshit
Research Associate,
Institute of Physics (IOP),
Bhubaneswar- 751 005
Orissa
India
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