[QE-users] Query about optB86b functional

[Mohammad Moaddeli]

This is OK.
For the case I was working on, no difference between PBE and revPBE
functionals predicted. So, I used the PBE ones from PSlibrary. Please
evaluate them for your case.
See the file <quantum_ESPRESSO>/Modules/funct.f90 and check the lines 84 to
135 (for qe_6.5 version) for standard labels can be used in "input_dft =
...".  For example: vdw-df, vdw-df2-b86r, etc. New options are available in
qe_6.6, for example: vdw-df3-opt2.

Regards,

Mohammad

ShirazU

On Wed, Sep 16, 2020 at 11:21 PM rekha sharma <rekha1997jpr at gmail.com>
wrote:

> Here I found revPBE PPs:
> http://theossrv1.epfl.ch/Main/Pseudopotentials
>
> So it is okay to use revPBE PPs from above link with
>   input_dft='vdW-DF-ob86',
>
> Or I need some more inputs to be inserted in the input file.
>
> Please confirm.
>
> Thank you very much.
>
>
> On Thu, Sep 17, 2020 at 12:07 AM rekha sharma <rekha1997jpr at gmail.com>
> wrote:
>
>> Dear Sir
>> Thank you very much for your prompt reply.
>>
>> I do not find revPBE PPs on the QE PPs webpage.
>>
>> How can I generate these?
>>
>> Or simply I can use below with PBE PPs.
>> !  vdw_corr='Grimme-D3',  (optB86b with vdw_corr did not work so I
>> removed it)
>>   input_dft='vdW-DF-ob86',
>>
>> Thank you very much.
>>
>> Rekha
>>
>> On Wed, Sep 16, 2020 at 11:53 PM Mohammad Moaddeli <
>> mohammad.moaddeli at gmail.com> wrote:
>>
>>> Dear Rekha,
>>>
>>> You do not need to generate the vdW table. It is on-the-fly in new
>>> versions of quantum ESPRESSO. To the best of my knowledge, you should use
>>> revPBE pseudo-potentials for vdW-optB86b functional. Check the paper on
>>> this functional. However, I always use PBE ones. but, remember not to use
>>> LDA + vdW (semi-empirical or ab-initio) for considering long-range
>>> interactions.
>>>
>>> see for example:
>>> https://journals.aps.org/prb/abstract/10.1103/PhysRevB.83.195131
>>> https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.91.126402
>>>
>>>
>>> Best,
>>>
>>> Mohammad
>>>
>>> ShirazU
>>>
>>> On Wed, Sep 16, 2020 at 10:34 PM rekha sharma <rekha1997jpr at gmail.com>
>>> wrote:
>>>
>>>> Dear Sir,
>>>> This is in connection with my previous email (how to use optB86b).
>>>>
>>>> Version of QE is 6.5.
>>>>
>>>> After a detailed search I found that I need to generate
>>>> vdW_kernel_table  using
>>>>
>>>> * generate_vdw_kernel_table.x*
>>>>
>>>> and then keep that table in the directory where we keep our PPs and
>>>> then we can use regular PPs with
>>>>
>>>> !  vdw_corr='Grimme-D3',  (optB86b with vdw_corr did not work so I
>>>> removed it)
>>>>   input_dft='vdW-DF-ob86',
>>>>
>>>> But I am not getting * generate_vdw_kernel_table.x on my system.*
>>>> How can I get it?
>>>>  Do I need to install some other libraries for it?
>>>>
>>>> Please help me.
>>>>
>>>> Thank you very much.
>>>>
>>>> Rekha
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, Sep 16, 2020 at 12:22 PM rekha sharma <rekha1997jpr at gmail.com>
>>>> wrote:
>>>>
>>>>> Dear Users,
>>>>> I want to simulate a carbon based layered materials where I want to
>>>>> use optB86b functional.
>>>>>
>>>>> I use:
>>>>>
>>>>> !  vdw_corr='Grimme-D3',  (optB86b with vdw_corr did not work so I
>>>>> removed it)
>>>>>   input_dft='vdW-DF-ob86',
>>>>>
>>>>> Can someone please confirm whether the regular Pseudopotentials
>>>>> available on Quantum Espresso Web-Page works  or for optB86b functional I
>>>>> need some other PPs?
>>>>>
>>>>>
>>>>> Thank you very much,
>>>>>
>>>>> Best regards
>>>>> Rekha
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Quantum ESPRESSO is supported by MaX (
>>>> www.max-centre.eu/quantum-espresso)
>>>> users mailing list users at lists.quantum-espresso.org
>>>> https://lists.quantum-espresso.org/mailman/listinfo/users
>>>
>>> _______________________________________________
>>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso
>>> )
>>> users mailing list users at lists.quantum-espresso.org
>>> https://lists.quantum-espresso.org/mailman/listinfo/users
>>
>>
>>
>>
>
> --
>
>
>
>
> Best wishes
>
> Ms. Rekha
> Teaching Assistant,
> Department of Physics
> RK college, Jaipur, India
> Mob.: +11 90-95 790 71 697
> Email: rekha1997jpr at gmail.com
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20200917/34a14823/attachment.html>