[QE-users] Fwd: problem in band gap

[Giuseppe Mattioli]

Your first reply did not reach the mailing list, so we have not been  
able to look at your input file, yet.
Best
Giuseppe

Quoting Neelam Swarnkar <neelamswarnkar35 at gmail.com>:

> and I am using QE-6.3 version.
>
> On Wed, May 6, 2020 at 9:21 PM Neelam Swarnkar <neelamswarnkar35 at gmail.com>
> wrote:
>
>> Dear Giuseppe & all
>>
>> I had plotted the band  gap which represent the metal type of material.
>> but in most of research paper ,its band gap =0.72 eV, or some reported a
>> range of band gap = 0.53 to 0.61 eV [1 ZnSbcomputational stydy], which
>> represent ZnSb semiconductor type of behavior.
>>
>> my plotted band gap attached here . I think , i have choose wrong
>> pseudopotential file.
>> So, pl. give me direction or guidelines to calculate semiconductor band
>> gap of ZnSb thermoelectric material.
>>
>>
>>
>> On Wed, May 6, 2020 at 6:08 PM Giuseppe Mattioli <
>> giuseppe.mattioli at ism.cnr.it> wrote:
>>
>>>
>>> Dear Neelam Swarnkar
>>> What do you mean when you say "correct band gap"? A literature
>>> experimental value? A literature calculated value? In the former case,
>>> the compatibility depends on the exchange-correlation functional you
>>> use. There is plenty of literature on this, you just have to type "DFT
>>> underestimation band gap" in google to have an idea. In the latter
>>> case, if you are trying to reproduce the results of previous
>>> theoretical calculations, then you must use the same theoretical setup
>>> in a proper way, and it is impossible to help you if you don't post
>>> relevant information (QE version, input, ...)
>>> HTH
>>> Giuseppe
>>>
>>> Quoting Neelam Swarnkar <neelamswarnkar35 at gmail.com>:
>>>
>>> > ---------- Forwarded message ---------
>>> > From: <users-owner at lists.quantum-espresso.org>
>>> > Date: Wed, May 6, 2020, 3:25 PM
>>> > Subject: problem in band gap
>>> > To: <neelamswarnkar35 at gmail.com>
>>> >
>>> >
>>> > * You have to be subscribed to post
>>> >
>>> > * You have to post from EXACTLY the same email you used to subscribe
>>> >
>>> > * If you subscribed and did not receive the confirmation message,
>>> > check your spam folder
>>> >
>>> >
>>> >
>>> >
>>> > ---------- Forwarded message ----------
>>> > From: Neelam Swarnkar <neelamswarnkar35 at gmail.com>
>>> > To: users at lists.quantum-espresso.org
>>> > Cc:
>>> > Bcc:
>>> > Date: Wed, 6 May 2020 15:24:49 +0530
>>> > Subject: problem in band gap
>>> > Dear All
>>> >
>>> > I am new for using quantum espresso-6.3. i am calculating the scf ,nscf,
>>> > bands, etc of ZnSb thermoelectric material this material belongs to Pbca
>>> > (61) space group. and had orthorhombic crystal structure , no of
>>> electrons
>>> > =8.
>>> >
>>> >
>>> > I have done scf, nscf calculation and band calculation but not found the
>>> > correct band gap.
>>> >
>>> > I don't know what wrong in this , or may be choose wrong psedopotential.
>>> >
>>> > please explain to me  , correct way to calculate correct band gap.
>>> > Zn.in    and Zn.out is my scf calculation.
>>> >
>>> > QE-user
>>> > Neelam Swarnkar
>>> > Phd scholar
>>>
>>>
>>>
>>> GIUSEPPE MATTIOLI
>>> CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
>>> Via Salaria Km 29,300 - C.P. 10
>>> I-00015 - Monterotondo Scalo (RM)
>>> Mob (*preferred*) +39 373 7305625
>>> Tel + 39 06 90672342 - Fax +39 06 90672316
>>> E-mail: <giuseppe.mattioli at ism.cnr.it>
>>>
>>> _______________________________________________
>>> 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
>>>
>>



GIUSEPPE MATTIOLI
CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
Via Salaria Km 29,300 - C.P. 10
I-00015 - Monterotondo Scalo (RM)
Mob (*preferred*) +39 373 7305625
Tel + 39 06 90672342 - Fax +39 06 90672316
E-mail: <giuseppe.mattioli at ism.cnr.it>