[CP2K-user] [CP2K:19291] Band gap-HSE06-UiO-66

[Matt Watkins]

Hi,
I'd try running with a bigger primary basis set (TZVP) and see if the band 
gap is sensitive to this.
Matt

On Wednesday, 4 October 2023 at 02:30:42 UTC+1 Jingyun Ye wrote:

> Hello Lucas, 
>
> Thank you for sharing your thoughts. So normally for the MOFs system, 
> either VASP or CP2K, gama point is usually selected for calculation since 
> the unit cell has several hundreds of atoms. For the test materials, it 
> only has the direct band gap. 
>
> The xyz coordinate, lattice constants are the same for both VASP and CP2K 
> tests. 
>
> I don't think it is because of  EPS_DEFAULT, EPS_PGF_ORB because they are 
> in the magnitudes of -14, and -60. 
>
> I used the basis set: DZVP and auxiliary basis set (ADMM): a 
> combination of c-FIT11 and cFIT3, which are the maximum I can afford, or 
> else, the calculation will run out of memory. I think this might be the 
> case for the large systems.  
>
> Could you please share more about the CUTOFF? You mean the GHT basis set 
> (400) and plane wave cutoff (60), right? I think my cutoff is reasonable 
> since I test the convergence for energy but for PBE functional. 
>
> I think this will be a very helpful discussion for all. 
>
> Thank you,
> Jenny 
>
>
>
>
>
> On Tue, Oct 3, 2023 at 6:48 PM Lucas Lodeiro <eluni... at gmail.com> wrote:
>
>> Hello Jenny,
>>
>> AFAIK HSE functional is shortrange functional by definition... it is 
>> constructed using the erf(wr) technique and leaving only the short range 
>> term. WRT the value of the band gap, the band gap is very dependent on the 
>> reciprocal space sampling, whether the band gap is not vertical in 
>> reciprocal space or either the eigenvalues are highly dependent on the 
>> sampling, so I guess you use kpoints in VASP, did you use the same 
>> structure/cell and kpoints in CP2K instead? This is very important to 
>> compare both results.
>> Also, the accuracy must be set by your calculation settings, as 
>> EPS_DEFAULT, EPS_PGF_ORB, your basis set and auxiliary basis set (ADMM). 
>> Also the possible screening for the HF part, and the cutoff, which must be 
>> sufficient long to ensure the short range decay to low values...
>> Regards - Lucas
>>
>> El mar, 3 oct 2023 a las 17:37, jingyu... at gmail.com (<jingyu... at gmail.com>) 
>> escribió:
>>
>>> Hello everyone,
>>>
>>> I am trying to compare with HSE06 functional using VASP and CP2K. I 
>>> found out that the band gap calculated using VASP is about 3.7 eV for 
>>> UiO-66 which is very close to the experimental value 3.6-3.7 eV. 
>>>
>>> However, when I use CP2K, the band gap is 4.07 eV, which is almost the 
>>> same with the data reported by the following paper.  (Understanding 
>>> Intrinsic Light Absorption Properties of UiO-66 Frameworks: A Combined 
>>> Theoretical and Experimental Study, *Inorg. Chem.* 2015, 54, 22, 
>>> 10701–10710) 
>>>
>>> I wonder if the developer could comment on the accuracy? Or any room to 
>>> improve the accuracy.  (HSE06 functional section I used is the default 
>>> that posted on the CP2K website or lectures by Dr. Sanliang Ling. ) 
>>>
>>> Another question: Only shortrange keyword is allowed to use for HSE06? 
>>>
>>> Thank you, 
>>> Jenny 
>>>
>>> -- 
>>> You received this message because you are subscribed to the Google 
>>> Groups "cp2k" group.
>>> To unsubscribe from this group and stop receiving emails from it, send 
>>> an email to cp2k+uns... at googlegroups.com.
>>> To view this discussion on the web visit 
>>> https://groups.google.com/d/msgid/cp2k/7c9518cd-8f3c-4d1e-acb8-0b89caed128dn%40googlegroups.com 
>>> <https://groups.google.com/d/msgid/cp2k/7c9518cd-8f3c-4d1e-acb8-0b89caed128dn%40googlegroups.com?utm_medium=email&utm_source=footer>
>>> .
>>>
>> -- 
>>
> You received this message because you are subscribed to a topic in the 
>> Google Groups "cp2k" group.
>> To unsubscribe from this topic, visit 
>> https://groups.google.com/d/topic/cp2k/KgKHoHhouyc/unsubscribe.
>> To unsubscribe from this group and all its topics, send an email to 
>> cp2k+uns... at googlegroups.com.
>> To view this discussion on the web visit 
>> https://groups.google.com/d/msgid/cp2k/CAOFT4PJUcj-bNDGAfo49wc7wMLy9E5KK2-mOTPJ%2ByPnH%3D4psqQ%40mail.gmail.com 
>> <https://groups.google.com/d/msgid/cp2k/CAOFT4PJUcj-bNDGAfo49wc7wMLy9E5KK2-mOTPJ%2ByPnH%3D4psqQ%40mail.gmail.com?utm_medium=email&utm_source=footer>
>> .
>>
>

-- 
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/bce35fe4-3e0b-4d17-af9f-952115e28311n%40googlegroups.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20231003/717ea988/attachment-0001.htm>